Browse publications by year: 2021

Fulltext Actinobacteria: An eco-friendly and promising technology for the bioaugmentation of contaminants

Mawang CI, Azman AS, Fuad AM, Ahamad M

Biotechnol Rep (Amst), 2021 Dec;32:e00679.
PMID: 34660214 DOI: 10.1016/j.btre.2021.e00679

Over the past two decades, various eco-friendly approaches utilizing microbial species to clean up contaminated environments have surfaced. In this aspect, actinobacteria have demonstrated their potential in contaminant degradation. The members of actinobacteria phylum exhibits a cosmopolitan distribution, which means that they can be found widely in both aquatic and terrestrial ecosystems. Actinobacteria play important ecological roles in the environment, such as degrading complex polymers, recycling compounds, and producing bioactive molecules. Hence, using actinobacteria to clean up contaminants is an attractive method in the field of biotechnology. This can be achieved through the green technology of bioaugmentation, whereby the degradative capacity of contaminated areas can be greatly improved through the introduction of specific microorganisms. This review describes actinobacteria as an eco-friendly and a promising technology for the bioaugmentation of contaminants, with focus on pesticides and heavy metals.
Fulltext Multi-target weapons: diaryl-pyrazoline thiazolidinediones simultaneously targeting VEGFR-2 and HDAC cancer hallmarks

Upadhyay N, Tilekar K, Safuan S, Kumar AP, Schweipert M, Meyer-Almes FJ, et al.

RSC Med Chem, 2021 Sep 23;12(9):1540-1554.
PMID: 34671737 DOI: 10.1039/d1md00125f

In anticancer drug discovery, multi-targeting compounds have been beneficial due to their advantages over single-targeting compounds. For instance, VEGFR-2 has a crucial role in angiogenesis and cancer management, whereas HDACs are well-known regulators of epigenetics and have been known to contribute significantly to angiogenesis and carcinogenesis. Herein, we have reported nineteen novel VEGFR-2 and HDAC dual-targeting analogs containing diaryl-pyrazoline thiazolidinediones and their in vitro and in vivo biological evaluation. In particular, the most promising compound 14c has emerged as a dual inhibitor of VEGFR-2 and HDAC. It demonstrated anti-angiogenic activity by inhibiting in vitro HUVEC proliferation, migration, and tube formation. Moreover, an in vivo CAM assay showed that 14c repressed new capillary formation in CAMs. In particular, 14c exhibited cytotoxicity potential on different cancer cell lines such as MCF-7, K562, A549, and HT-29. Additionally, 14c demonstrated significant potency and selectivity against HDAC4 in the sub-micromolar range. To materialize the hypothesis, we also performed molecular docking on the crystal structures of both VEGFR-2 (PDB ID: 1YWN) and HDAC4 (PDB-ID: 4CBY), which corroborated the designing and biological activity. The results indicated that compound 14c could be a potential lead to develop more optimized multi-target analogs with enhanced potency and selectivity.
Fulltext The Pandemic Experience in Southeast Asia: Interface Between SARS-CoV-2, Malaria, and Dengue

Yek C, Nam VS, Leang R, Parker DM, Heng S, Souv K, et al.

Front Trop Dis, 2021;2.
PMID: 35373190 DOI: 10.3389/fitd.2021.788590

Southeast Asia (SEA) emerged relatively unscathed from the first year of the global SARS-CoV-2 pandemic, but as of July 2021 the region is experiencing a surge in case numbers primarily driven by Alpha (B.1.1.7) and subsequently the more transmissible Delta (B.1.617.2) variants. While initial disease burden was mitigated by swift government responses, favorable cultural and societal factors, the more recent rise in cases suggests an under-appreciation of prior prevalence and over-appreciation of possible cross-protective immunity from exposure to endemic viruses, and highlights the effects of vaccine rollout at varying tempos and of variable efficacy. This burgeoning crisis is further complicated by co-existence of malaria and dengue in the region, with implications of serological cross-reactivity on interpretation of SARS-CoV-2 assays and competing resource demands impacting efforts to contain both endemic and pandemic disease.
Fulltext Drug Delivery of Natural Products Through Nanocarriers for Effective Breast Cancer Therapy: A Comprehensive Review of Literature

Yap KM, Sekar M, Fuloria S, Wu YS, Gan SH, Mat Rani NNI, et al.

Int J Nanomedicine, 2021;16:7891-7941.
PMID: 34880614 DOI: 10.2147/IJN.S328135

Despite recent advances in the diagnosis and treatment of breast cancer (BC), it remains a global health issue affecting millions of women annually. Poor prognosis in BC patients is often linked to drug resistance as well as the lack of effective therapeutic options for metastatic and triple-negative BC. In response to these unmet needs, extensive research efforts have been devoted to exploring the anti-BC potentials of natural products owing to their multi-target mechanisms of action and good safety profiles. Various medicinal plant extracts/essential oils and natural bioactive compounds have demonstrated anti-cancer activities in preclinical BC models. Despite the promising preclinical results, however, the clinical translation of natural products has often been hindered by their poor stability, aqueous solubility and bioavailability. There have been attempts to overcome these limitations, particularly via the use of nano-based drug delivery systems (NDDSs). This review highlights the tumour targeting mechanisms of NDDSs, the advantages and disadvantages of the major classes of NDDSs and their current clinical status in BC treatment. Besides, it also discusses the proposed anti-BC mechanisms and nanoformulations of nine medicinal plants' extracts/essential oils and nine natural bioactive compounds; selected via the screening of various scientific databases, including PubMed, Scopus and Google Scholar, based on the following keywords: "Natural Product AND Nanoparticle AND Breast Cancer". Overall, these nanoformulations exhibit improved anti-cancer efficacy against preclinical BC models, with some demonstrating biocompatibility with normal cell lines and mouse models. Further clinical studies are, however, warranted to ascertain their efficacy and biocompatibility in humans.

MeSH terms: Animals; Female; Humans; Plants, Medicinal*; Drug Delivery Systems; Mice
Fulltext Modelling of Stem Cells Microenvironment Using Carbon-Based Scaffold for Tissue Engineering Application-A Review

Vitus V, Ibrahim F, Wan Kamarul Zaman WS

Polymers (Basel), 2021 Nov 23;13(23).
PMID: 34883564 DOI: 10.3390/polym13234058

A scaffold is a crucial biological substitute designed to aid the treatment of damaged tissue caused by trauma and disease. Various scaffolds are developed with different materials, known as biomaterials, and have shown to be a potential tool to facilitate in vitro cell growth, proliferation, and differentiation. Among the materials studied, carbon materials are potential biomaterials that can be used to develop scaffolds for cell growth. Recently, many researchers have attempted to build a scaffold following the origin of the tissue cell by mimicking the pattern of their extracellular matrix (ECM). In addition, extensive studies were performed on the various parameters that could influence cell behaviour. Previous studies have shown that various factors should be considered in scaffold production, including the porosity, pore size, topography, mechanical properties, wettability, and electroconductivity, which are essential in facilitating cellular response on the scaffold. These interferential factors will help determine the appropriate architecture of the carbon-based scaffold, influencing stem cell (SC) response. Hence, this paper reviews the potential of carbon as a biomaterial for scaffold development. This paper also discusses several crucial factors that can influence the feasibility of the carbon-based scaffold architecture in supporting the efficacy and viability of SCs.
Fulltext Past and Current Progress in the Development of Antiviral/Antimicrobial Polymer Coating towards COVID-19 Prevention: A Review

Nasri N, Rusli A, Teramoto N, Jaafar M, Ku Ishak KM, Shafiq MD, et al.

Polymers (Basel), 2021 Dec 02;13(23).
PMID: 34883737 DOI: 10.3390/polym13234234

The astonishing outbreak of SARS-CoV-2 coronavirus, known as COVID-19, has attracted numerous research interests, particularly regarding fabricating antimicrobial surface coatings. This initiative is aimed at overcoming and minimizing viral and bacterial transmission to the human. When contaminated droplets from an infected individual land onto common surfaces, SARS-CoV-2 coronavirus is able to survive on various surfaces for up to 9 days. Thus, the possibility of virus transmission increases after touching or being in contact with contaminated surfaces. Herein, we aim to provide overviews of various types of antiviral and antimicrobial coating agents, such as antimicrobial polymer-based coating, metal-based coating, functional nanomaterial, and nanocomposite-based coating. The action mode for each type of antimicrobial agent against pathogens is elaborated. In addition, surface properties of the designed antiviral and antimicrobial polymer coating with their influencing factors are discussed in this review. This paper also exhibits several techniques on surface modification to improve surface properties. Various developed research on the development of antiviral/antimicrobial polymer coating to curb the COVID-19 pandemic are also presented in this review.
Fulltext Postoperative management of zones V-VI extensor tendon repairs: A survey of practice in Malaysia and comparison to IFSHT member countries

Howell JW, Hirth MJ, Chai SC, Brown T, O'Brien L

Hand Ther, 2021 Dec;26(4):134-145.
PMID: 37904834 DOI: 10.1177/17589983211031259

INTRODUCTION: A survey of International Federation of Societies for Hand Therapy (IFSHT) member countries identified relative motion extension as the preferred approach to management of zones V-VI extensor tendon repairs. The aims of this survey were to identify and compare hand therapy practice patterns in Malaysia (a non-IFSHT member country) with findings of the IFSHT survey including an IFSHT subset of Asia-Pacific therapists and to investigate if membership status of the Malaysian Society for Hand Therapists (MSHT) influenced therapy practice patterns.
METHODS: An online English-language survey was distributed to 90 occupational therapists and physiotherapists including MSHT members and non-members. Participation required management of at least one extensor tendon repair in the preceding year. Five approaches were surveyed: immobilisation, early passive motion (EPM) with dynamic splinting, and early active motion (EAM) delivered by resting hand (RH), palmar resting interphalangeal joints free (PR), and relative motion extension (RME) splints.
RESULTS: Thirty-seven of the 53 therapists (68%) who commenced the survey completed it. The most used approach was dynamic/EPM (28%), followed by RH/immobilisation (22%) and RH/EAM (22%). A preference for RME/EAM was identified with implementation barriers being surgeon preference and hand therapist confidence.
DISCUSSION: Approach selection for Malaysian therapists differed from the combined IFSHT and Asia-Pacific respondents, with the former using dynamic/EPM and RH/immobilisation compared to IFSHT respondents who predominately used RME/EAM and PR/EAM. This survey provides valuable insights into Malaysian hand therapists' practices. If implementation barriers and therapist confidence are addressed, Malaysian practice patterns may change to better align with current evidence.
Integrating augmented reality technology in education: vector personal computer augmented reality

Tan SY, Tay NNW

F1000Res, 2021;10:987.
PMID: 37767360 DOI: 10.12688/f1000research.72948.2

Background: Educators often face difficulties in explaining abstract concepts such as vectors. During the ongoing coronavirus disease 2019 (COVID-19) pandemic, fully online classes have also caused additional challenges to using conventional teaching methods. To explain a vector concept of more than 2 dimensions, visualization becomes a problem. Although Microsoft PowerPoint can integrate animation, the illustration is still in 2-dimensions. Augmented reality (AR) technology is recommended to aid educators and students in teaching-learning vectors, namely via a vector personal computer augmented reality system (VPCAR), to fulfil the demand for tools to support the learning and teaching of vectors. Methods: A PC learning module for vectors was developed in a 3-dimensional coordinate system by using AR technology. Purposive sampling was applied to get feedback from educators and students in Malaysia through an online survey. The supportiveness of using VPCAR based on six items (attractiveness, easiness, visualization, conceptual understanding, inspiration and helpfulness) was recorded on 5-points Likert-type scales. Findings are presented descriptively and graphically. Results: Surprisingly, both students and educators adapted to the new technology easily and provided significant positive feedback that showed a left-skewed and J-shaped distribution for each measurement item, respectively. The distributions were proven significantly different among the students and educators, where supportive level result of educators was higher than students. This study introduced a PC learning module other than mobile apps as students mostly use laptops to attend online class and educators also engage other IT tools in their teaching. Conclusions: Based on these findings, VPCAR provides a good prospect in supporting educators and students during their online teaching-learning process. However, the findings may not be generalizable to all students and educators in Malaysia as purposive sampling was applied. Further studies may focus on government-funded schools using the newly developed VPCAR system, which is the novelty of this study.
Fulltext Pancreatic cancer grading in pathological images using deep learning convolutional neural networks

Mohamad Sehmi MN, Ahmad Fauzi MF, Wan Ahmad WSHM, Wan Ling Chan E

F1000Res, 2021;10:1057.
PMID: 37767358 DOI: 10.12688/f1000research.73161.2

Background: Pancreatic cancer is one of the deadliest forms of cancer. The cancer grades define how aggressively the cancer will spread and give indication for doctors to make proper prognosis and treatment. The current method of pancreatic cancer grading, by means of manual examination of the cancerous tissue following a biopsy, is time consuming and often results in misdiagnosis and thus incorrect treatment. This paper presents an automated grading system for pancreatic cancer from pathology images developed by comparing deep learning models on two different pathological stains. Methods: A transfer-learning technique was adopted by testing the method on 14 different ImageNet pre-trained models. The models were fine-tuned to be trained with our dataset. Results: From the experiment, DenseNet models appeared to be the best at classifying the validation set with up to 95.61% accuracy in grading pancreatic cancer despite the small sample set. Conclusions: To the best of our knowledge, this is the first work in grading pancreatic cancer based on pathology images. Previous works have either focused only on detection (benign or malignant), or on radiology images (computerized tomography [CT], magnetic resonance imaging [MRI] etc.). The proposed system can be very useful to pathologists in facilitating an automated or semi-automated cancer grading system, which can address the problems found in manual grading.
18F-PSMA-1007 PET/CT for Initial Staging of Renal Cell Carcinoma in an End-Stage Renal Disease Patient

Marafi F, Sasikumar A, Aldaas M, Esmail A

Clin Nucl Med, 2021 Jan;46(1):e65-e67.
PMID: 33181733 DOI: 10.1097/RLU.0000000000003354

A 46-year-old man with end-stage renal disease and renal cell carcinoma underwent F-FDG PET/CT for initial staging followed by F-PSMA-1007 PET/CT. Unlike F-FDG, which undergoes renal clearance, F-PSMA-1007 undergoes hepatobiliary clearance and thus generates superior quality images. F-PSMA-1007 PET/CT showed intense tracer-avid left renal mass lesion (FDG nonavid); lytic bone lesions (FDG avid) and single liver lesion (FDG nonavid). This case highlights the superiority of F-PSMA-1007 over F-FDG PET/CT in identifying primary lesion as well as metastatic sites in case of renal cell carcinoma even in the presence of end-stage renal disease.

MeSH terms: Carcinoma, Renal Cell/complications; Carcinoma, Renal Cell/pathology*; Female; Fluorine Radioisotopes; Humans; Kidney Failure, Chronic/complications*; Kidney Neoplasms/complications; Kidney Neoplasms/pathology*; Middle Aged; Neoplasm Staging; Niacinamide/analogs & derivatives*; Oligopeptides*; Positron Emission Tomography Computed Tomography*
Numerical model for enhancing stimulated Brillouin scattering in optical microfibers

Yeap SH, Emami SD, Abdul-Rashid HA

F1000Res, 2021;10:521.
PMID: 37745939 DOI: 10.12688/f1000research.51029.2

Stimulated Brillouin scattering (SBS) is useful, among others for generating slow light, sensing and amplification. SBS was previously viewed as a poor method due to the limitation on optical power in high-powered photonic applications. However, considering the many possible applications using SBS, it is now of interest to enhance SBS in areas of Brillouin frequency shift together with Brillouin Gain. A numerical model, using a fully vectorial approach, by employing the finite element method, was developed to investigate methods for enhancing SBS in optical fiber. This paper describes the method related to the numerical model and discusses the analysis between the interactions of longitudinal, shear and hybrid acoustic modes; and optical modes in optical fiber. Two case studies were used to demonstrate this. Based on this numerical model, we report the influence of core radius, clad radius and effective refractive index on the Brillouin frequency shift and gain. We observe the difference of Brillouin shift frequency between a normal silica optical fiber and that of a microfiber - a uniformed silica fiber of a much smaller core and cladding dimensions where nonlinearities are higher. Also observed, the different core radii used and their respective Brillouin shift. For future work, the COMSOL model can also be used for the following areas of research, including simulating "surface Brillouin shift" and also to provide in-sights to the Brillouin shift frequency vB of various structures of waveguides, e.g circular, and triangular, and also to examine specialty fibers, e.g. Thulium and Chalcogenide doped fibers, and their effects on Brillouin shift frequency.
Fulltext Predictors of Persistence of Anxiety, Hyperarousal Stress, and Resilience During the COVID-19 Epidemic: A National Study in Iran

Sharif Nia H, Akhlaghi E, Torkian S, Khosravi V, Etesami R, Froelicher ES, et al.

Front Psychol, 2021;12:671124.
PMID: 34658994 DOI: 10.3389/fpsyg.2021.671124

Background: The coronavirus pandemic can cause unprecedented global anxiety, and, in contrast, resilience can help the mental health of people in stressful situations. This study aimed to assess anxiety, hyperarousal stress, the resilience of the Iranian population, and their related factors during the coronavirus disease 2019 (COVID-19) epidemic. Methods: A cross-sectional study was conducted in 31 provinces in Iran between March 18 and 25, 2020. A four-part questionnaire, including the demographic information, the State-Trait Anxiety Inventory (STAI-y1-a 20-item standard questionnaire for obvious anxiety), the Connor-Davidson Resilience Scale (CD-RISC-a 25 item standard questionnaire), and the stress hyperarousal subscale from the Impact of Event Scale-Revised (IES-R), was used to collect data. The ordinal multivariable generalized estimating equation (GEE) model was used to identify correlates of the psychological factors mentioned above. The Fisher exact test was used to investigate the relationship between anxiety, stress, resilience, and the COVID-19 outbreak. All analyses were conducted with SPSS 26 and GIS 10.71. Results: The findings show that most people had moderate-to-severe anxiety (80.17%) and a high level of resilience (96.4%) during the COVID-19 epidemic. The majority of participants had a moderate level of stress (58.9%). The lowest and highest prevalences of psychiatric disorders were in Sistan and Baluchestan (3.14 cases per 100,000 people) and Semnan (75.9 cases per 100,000 people) provinces, respectively. Men and unmarried people were the only variables significantly associated with anxiety and resilience. Age, gender, and education were significantly associated with hyperarousal stress. Conclusion: The high and moderate levels of anxiety and stress in Iranians can have negative effects on the well-being and performance of the people and can lead to serious problems. Also, high resilience during negative life events (such as the COVID-19 pandemic) is associated with the well-being in the lives of people. The results of this study can be used in interventions and other psychological studies.
Fulltext COVID-19 Disruptions in Health Professional Education: Use of Cognitive Load Theory on Students' Comprehension, Cognitive Load, Engagement, and Motivation

Hadie SNH, Tan VPS, Omar N, Nik Mohd Alwi NA, Lim HL, Ku Marsilla KI

Front Med (Lausanne), 2021;8:739238.
PMID: 34671622 DOI: 10.3389/fmed.2021.739238

This study explored the impact of online lectures that were developed using principles of cognitive load theory (CLT) and cognitive theory of multimedia learning (CTML) on health profession students' lecture comprehension, cognitive load, cognitive engagement, and intrinsic motivation in learning. A total of 215 first-year undergraduate students in medical, dentistry, and nutrition programs participated in this pre-post quasi experimental study. The students attended a typical face-to-face lecture on Day-1 of the intervention, followed by a CLT-based online lecture 8 weeks thereafter. Their comprehension of the lecture topics was measured through pre- and post-lecture assessments, and their cognitive load, cognitive engagement, and motivation were measured immediately after each lecture session. The analysis revealed that the CLT-based online lectures promoted the students' comprehension of the lecture content (p < 0.001), self-perceived learning (p < 0.001), engagement toward the learning material, and motivation to learn (p = 0.025). It was also effective at reducing the students' intrinsic and extraneous cognitive loads (p < 0.001). Hence, designing online lectures using CLT and CTML principles could be an effective method to promote students' knowledge and comprehension, cognitive engagement, and learning motivation. However, further research is needed to investigate the applicability and impact of CLT-based online lectures in non-health profession disciplines.
Fulltext Posttraumatic Growth and Coping Strategies Among Patients With Head and Neck Cancer: Do Approach Coping and Avoidant Coping Predict Posttraumatic Growth Over Time?

Nik Jaafar NR, Abd Hamid N, Hamdan NA, Rajandram RK, Mahadevan R, Mohamad Yunus MR, et al.

Front Psychol, 2021;12:716674.
PMID: 34764904 DOI: 10.3389/fpsyg.2021.716674

Despite an enormous number of studies addressing the importance of posttraumatic growth (PTG) among cancer patients, the literature lacks data regarding how different coping strategies affect PTG among head and neck cancer (HNC) patients over time. This longitudinal study investigated the PTG trend and coping over 5-7months among a cohort of HNC patients within the first year after their diagnosis. It determined an association between coping strategies and PTG over time. The study's HNC respondents were administered a socio-demographic and clinical characteristics questionnaire during their baseline assessments. Additionally, the Malay versions of the "PTG Inventory-Short Form" (PTGI-SF) and the "Brief Coping Orientation to Problems Experienced Inventory" (Brief COPE) were administered during respondents' baseline assessments and follow-up assessments (5-7months after the baseline assessments). In total, 200 respondents reported an increasing PTG trend and approach coping (active coping, planning, positive reframing, acceptance, emotional support, and instrumental support) and a decreasing trend of avoidant coping (self-distraction and denial) over time. Two approach coping strategies (acceptance and planning) significantly increased PTG while denial was the only avoidant coping strategy that significantly lowered PTG, after controlling for socio-demographic and clinical characteristics, over time. Our study's findings identified the need to incorporate psychosocial interventions that enhance approach coping and reduce avoidant coping into HNC patients' treatment regimes.
Fulltext Noise Eliminated Ensemble Empirical Mode Decomposition Scalogram Analysis for Rotating Machinery Fault Diagnosis

Faysal A, Ngui WK, Lim MH, Leong MS

Sensors (Basel), 2021 Dec 04;21(23).
PMID: 34884120 DOI: 10.3390/s21238114

Rotating machinery is one of the major components of industries that suffer from various faults due to the constant workload. Therefore, a fast and reliable fault diagnosis method is essential for machine condition monitoring. In this study, noise eliminated ensemble empirical mode decomposition (NEEEMD) was used for fault feature extraction. A convolution neural network (CNN) classifier was applied for classification because of its feature learning ability. A generalized CNN architecture was proposed to reduce the model training time. A sample size of 64×64×3 pixels RGB scalograms are used as the classifier input. However, CNN requires a large number of training data to achieve high accuracy and robustness. Deep convolution generative adversarial network (DCGAN) was applied for data augmentation during the training phase. To evaluate the effectiveness of the proposed feature extraction method, scalograms from related feature extraction methods such as ensemble empirical mode decomposition (EEMD), complementary EEMD (CEEMD), and continuous wavelet transform (CWT) are classified. The effectiveness of scalograms is also validated by comparing the classifier performance using grayscale samples from the raw vibration signals. All the outputs from bearing and blade fault classifiers showed that scalogram samples from the proposed NEEEMD method obtained the highest accuracy, sensitivity, and robustness using CNN. DCGAN was applied with the proposed NEEEMD scalograms to further increase the CNN classifier's performance and identify the optimal number of training data. After training the classifier using augmented samples, the results showed that the classifier obtained even higher validation and test accuracy with greater robustness. The proposed method can be used as a more generalized and robust method for rotating machinery fault diagnosis.

MeSH terms: Intelligence; Noise; Vibration; Neural Networks (Computer)*; Wavelet Analysis*
Fulltext Cytotoxicity of targeted PLGA nanoparticles: a systematic review

Chiu HI, Samad NA, Fang L, Lim V

RSC Adv, 2021 Mar 01;11(16):9433-9449.
PMID: 35423427 DOI: 10.1039/d1ra00074h

Recent advances in nanotechnology have contributed tremendously to the development and revolutionizing of drug delivery systems in the field of nanomedicine. In particular, targeting nanoparticles based on biodegradable poly(lactic-co-glycolic acid) (PLGA) polymers have gained much interest. However, PLGA nanoparticles remain of concern for their effectiveness against cancer cells and their toxicity to normal cells. The aim of this systematic review is to identify a promising targeting PLGA nanoformulation based on the comparison study of their cytotoxicity potency in different cell lines. A literature search was conducted through the databases of Google Scholar, PubMed, ScienceDirect, Scopus and SpringerLink. The sources studied were published between 2009 and 2019, and a variety of keywords were utilized. In total, 81 manuscripts that met the inclusion and exclusion criteria were selected for analysis based on their cytotoxicity, size, zeta potential, year of publication, type of ligand, active compounds and cell line used. The half maximal inhibitory concentration (IC50) for cytotoxicity was the main measurement in this data extraction, and the SI units were standardized to μg mL-1 for a better view of comparison. This systematic review also identified that cytotoxicity potency was inversely proportional to nanoparticle size. The PLGA nanoparticles predominantly exhibited a size of less than 300 nm and absolute zeta potential ∼20 mV. In conclusion, more comprehensive and critical appraisals of pharmacokinetic, pharmacokinetic, toxicokinetic, in vivo and in vitro tests are required for the investigation of the full value of targeting PLGA nanoparticles for cancer treatment.
Fulltext Including tree spatial extension in the evaluation of neighborhood competition effects in Bornean rain forest

Newbery DM, Stoll P

Ecol Evol, 2021 Jun;11(11):6195-6222.
PMID: 34141212 DOI: 10.1002/ece3.7452

Classical tree neighborhood models use size variables acting at point distances. In a new approach here, trees were spatially extended as a function of their crown sizes, represented impressionistically as points within crown areas. Extension was accompanied by plasticity in the form of crown removal or relocation under the overlap of taller trees. Root systems were supposedly extended in a similar manner. For the 38 most abundant species in the focal size class (10-<100 cm stem girth) in two 4-ha plots at Danum (Sabah), for periods P1 (1986-1996) and P2 (1996-2007), stem growth rate and tree survival were individually regressed against stem size, and neighborhood conspecific (CON) and heterospecific (HET) basal areas within incremented steps in radius. Model parameters were critically assessed, and statistical robustness in the modeling was set by randomization testing. Classical and extended models differed importantly in their outcomes. Crown extension weakened the relationship of CON effect on growth versus plot species' abundance, showing that models without plasticity overestimated negative density dependence. A significant negative trend of difference in CON effects on growth (P2-P1) versus CON or HET effect on survival in P1 was strongest with crown extension. Model outcomes did not then support an explanation of CON and HET effects being due to (asymmetric) competition for light alone. An alternative hypothesis is that changes in CON effects on small trees, largely incurred by a drought phase (relaxing light limitation) in P2, and following the more shaded (suppressing) conditions in P1, were likely due to species-specific (symmetric) root competition and mycorrhizal processes. The very high variation in neighborhood composition and abundances led to a strong "neighborhood stochasticity" and hence to largely idiosyncratic species' responses. A need to much better understand the roles of rooting structure and processes at the individual tree level was highlighted.
Fulltext Population-based Study Comparing Predictors of Ischemic Stroke Recurrence After Index Ischemic Stroke in Non-elderly Adults with or without Diabetes

Elhefnawy ME, Sheikh Ghadzi SM, Tangiisuran B, Zainal H, Looi I, Ibrahim KA, et al.

Int J Gen Med, 2021;14:1205-1212.
PMID: 33854362 DOI: 10.2147/IJGM.S303641

BACKGROUND AND PURPOSE: Factors associated with ischemic stroke (IS) recurrence and the contribution of pharmacological treatment as secondary preventions among nondiabetics especially in the non-elderly population are unclear and not widely investigated. This was a population-based study that aimed to identify recurrent IS predictors and to determine the possible impact of secondary preventive medications on the IS recurrence in non-elderly adults with or without diabetes.
METHODS: Data of 3386 patients <60 years old who had a history of index IS were extracted from the Malaysian National Neurology Registry (NNEUR) from 2009 to 2016. Recurrent IS was defined as any IS event recorded after the index IS in the NNEUR database. Multivariate logistic regression analysis was performed by using SPSS version 22.
RESULTS: Ischemic heart disease (IHD) was the significant predictor of IS recurrence in non-elderly adults both with or without diabetes (adjusted odds ratio (AOR) of 3.210; 95%CI: 1.909-5.398 and 2.989; 95%CI: 1.515-5.894) respectively). Receiving antiplatelet as secondary stroke prevention (AOR: 0.194; 95%CI: 0.046-0.817) and continuation of antidiabetic medication after the index IS event (AOR: 0.510; 95%CI: 0.298-0.872) reduced the odds of IS recurrence only in non-elderly diabetic adults. Among non-elderly adults without diabetes, hyperlipidemia and every increased in 1 mmHg of systolic blood pressure significantly increased the odds of IS recurrence following the indexing event (AOR: 1.796; 95%CI: 1.058-3.051 and 1.009; 95%CI: 1.002-1.016 respectively).
CONCLUSION: IHD was found as the main predictor of IS recurrence regardless of diabetes status in non-elderly adults after the index IS event. Receiving antidiabetic and antiplatelet medications upon discharge after index IS were significant predictors of recurrent IS in non-elderly diabetic adults. A proper randomized clinical trial may be required to determine the impact of secondary preventive medication on IS recurrence, especially in non-elderly adults.
Unsplinted Attachment Systems and Peri-implant Outcomes in Two-implant-retained Mandibular Overdentures: A Systematic Review of Randomized Controlled Trials

Patil PG, Seow LL, Kweh TJ, Nimbalkar S

J Contemp Dent Pract, 2021 Nov 01;22(11):1346-1354.
PMID: 35343463

AIM: The purpose of this review is to compare randomized clinical trials evaluating the peri-implant tissue outcomes using different unsplinted attachment systems in two implant-retained mandibular overdentures.
BACKGROUND: Literature lacks information on various unsplinted attachment systems and their effect on peri-implant tissue health. A focus question (as per PICOS) was set as follows: Does one particular unsplinted attachment system (I) compared with another (C) results in better peri-implant outcomes (O) in two implant-retained mandibular overdentures (P) using randomized controlled trials (RCTs) (S)? The literature search was conducted in the PubMed, MEDLINE and Cochrane Central Register of Controlled Trials (CENTRAL) databases between January 2011 and December 2021. The keywords used were "denture, overlay," "denture," "overlay" AND "dental prosthesis, implant supported," "dental implants," "dental implant abutment design" AND "jaw, edentulous," "mouth, edentulous" AND "mandible." Only RCTs on two implant-retained mandibular overdentures using unsplinted attachment systems measuring peri-implant tissue outcomes with minimum 1-year follow-up were selected. In total, 224 studies were identified in initial search, and 25 were shortlisted for full-text evaluation. Four studies were included for systematic review upon considering inclusion and exclusion criteria. The risk of bias was evaluated using Cochrane Risk of Bias Tool 2.0 (RoB 2.0).
REVIEW RESULTS: A total of 41 patients received ball attachments (in 3 studies), 36 patients received low-profile attachments (in 3 studies), 16 patients received magnet attachments (in 1 study), and 13 patients received telescopic attachments (in 1 study). All four studies used standard sized implants, however, differed in implant manufacturers. Two studies which compared ball attachments low-profile attachments revealed-similar peri-implant tissue health parameters but differed in crestal bone-level changes. One study compared ball with telescopic attachments and revealed similar results in crestal bone-level changes and all four peri-implant tissue health parameters. Single study compared magnets with low-profile attachments and shown lesser bone loss with magnet attachments. Single study was judged to have low risk of bias, single with some concerns, and remaining two to have high risk of bias.
CONCLUSION: Gingival index and bleeding index of the patients were not influenced by any of the unsplinted overdenture attachment (stud, magnet, telescopic) system. Inconclusive results found among the studies evaluated comparing crestal bone loss and plaque index.
CLINICAL SIGNIFICANCE: This review manuscript has simplified comparative analysis of different unsplinted attachment systems used in two implant mandibular overdentures to help clinicians choose correct system in such situation.

MeSH terms: Denture Retention/methods; Denture, Overlay*; Humans; Jaw, Edentulous*; Mandible; Randomized Controlled Trials as Topic; Dental Prosthesis, Implant-Supported
Fulltext Editorial: Malnutrition: A Cause or a Consequence of Poverty?

Ma ZF, Wang CW, Lee YY

Front Public Health, 2021;9:796435.
PMID: 35059381 DOI: 10.3389/fpubh.2021.796435

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