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First report of Cryptosporidium deer-like genotype in Malaysian cattle

Halim NA, Plutzer J, Bakheit MA, Karanis P

Vet Parasitol, 2008 Apr 15;152(3-4):325-9.
PMID: 18289793 DOI: 10.1016/j.vetpar.2007.12.035

Fifty faecal samples from diarrheic calves between 1 and 6 months old were collected per rectum from 5 farms around Petaling District in Selangor, Malaysia for Cryptosporidium species detection and genotyping investigation. Oocysts were purified using sedimentation and gradient centrifugation, then examined by immunofluorescence assay (IFAT). Genomic DNA was extracted from all samples and nested PCR was performed to amplify the SSU rRNA gene. Eighteen samples (36%) were positive for Cryptosporidium species by PCR. The sequence and phylogenetic analysis of 14 isolates indicated that Cryptosporidium parvum was most common (11 isolates) followed by Cryptosporidium deer-like genotype (3 isolates). The present work reports the first data on Cryptosporidium genotyping from cattle in Malaysia.
Fulltext Post-traumatic growth after cancer: a scoping review of qualitative research

Menger F, Mohammed Halim NA, Rimmer B, Sharp L

Support Care Cancer, 2021 Nov;29(11):7013-7027.
PMID: 34018030 DOI: 10.1007/s00520-021-06253-2

PURPOSE: Interest is growing in post-traumatic growth (PTG) after cancer prompted, in part, by observations of positive associations with health-related quality of life. Qualitative research provides valuable insight into survivors' experiences. We conducted a scoping review of qualitative evidence on PTG in cancer, determining the number, nature, range and scope of studies, and gaps in the literature.
METHODS: We systematically searched Medline, Scopus, CINAHL, Web of Science, and PsycINFO for qualitative research exploring positive changes after cancer published from 1996. From eligible studies, we extracted: terms used for PTG; design, methodological orientation, and techniques, and participant characteristics. Using descriptive mapping, we explored whether study findings fit within Tedeschi and Calhoun's PTG framework, and evidence for unique positive changes post-cancer.
RESULTS: Twenty-eight studies were eligible. Cancer sites included were: breast, 14; mixed, 6; haematological, 4; head and neck cancer, 2; bone, 1, and testis, 1. Multiple studies were conducted in: the USA (12), Australia (3), Iran (2), and the UK (2). Twenty-three studies collected data using individual interviews (21) or focus groups (2). Definitions of PTG varied. Studies largely focused on descriptive accounts of PTG. Findings mapped onto existing PTG dimensions; health behaviour changes were often reported, under 'new possibilities'.
CONCLUSIONS: A range of PTG outcomes can occur after cancer. Positive health behaviour changes warrant further exploration. Future research should include more diverse patient populations, collect longitudinal data, and focus on pathways towards positive changes.
Fulltext Nanomaterials-Upconverted Hydroxyapatite for Bone Tissue Engineering and a Platform for Drug Delivery

Abdul Halim NA, Hussein MZ, Kandar MK

Int J Nanomedicine, 2021;16:6477-6496.
PMID: 34584412 DOI: 10.2147/IJN.S298936

Hydroxyapatite is a basic mineral that is very important to the human body framework. Recently, synthetic hydroxyapatite (SHA) and its nanocomposites (HANs) are the subject of intense research for bone tissue engineering and drug loading system applications, due to their unique, tailor-made characteristics, as well as their similarities with the bone mineral component in the human body. Although hydroxyapatite has good biocompatibility and osteoconductive characteristics, the poor mechanical strength restricts its use in non-load-bearing applications. Consequently, a rapid increase in reinforcing of other nanomaterials into hydroxyapatite for the formation of HANs could improve the mechanical properties. Most of the research reported on the success of other nanomaterials such as metals, ceramics and natural/synthetic polymers as additions into hydroxyapatite is reviewed. In addition, this review also focuses on the addition of various substances into hydroxyapatite for the formation of various HANs and at the same time to try to minimize the limitations so that various bone tissue engineering and drug loading system applications can be exploited.
Fulltext Vanishing lung syndrome Masquerading as bilateral pneumothorax: A case report

Muhamad NI, Mohd Nawi SN, Yusoff BM, Ab Halim NA, Mohammad N, Wan Ghazali WS

Respir Med Case Rep, 2020;31:101276.
PMID: 33209576 DOI: 10.1016/j.rmcr.2020.101276

Vanishing lung syndrome (VLS) is a rare condition characterized by giant emphysematous bullae. It is frequently misdiagnosed as pneumothorax. We describe a case of a 30-year-old male who presented with shortness of breath, reduced effort tolerance, and pleuritic chest pain for three months. He was initially diagnosed with bilateral pneumothorax based on clinical examination and chest radiograph findings. However, further imaging with a high resolution computed tomography (HRCT) of the thorax confirmed bilateral giant emphysematous bullae. Our patient subsequently underwent video-assisted thoracoscopic surgery (VATS) and bullectomy. In this report, we discuss the clinical presentations, radiological features, and the management of VLS. We also highlight the differentiating features of VLS from a pneumothorax.
Demographic, clinical and laboratory features of leptospirosis and dengue co-infection in Malaysia

Hishamshah M, Ahmad N, Mohd Ibrahim H, Nur Halim NA, Nawi S, Amran F

J Med Microbiol, 2018 Jun;67(6):806-813.
PMID: 29724267 DOI: 10.1099/jmm.0.000750

Purpose. In this study, we aim to describe and compare the demographical, clinical and laboratory features of leptospirosis and dengue co-infections (LDCI) against single leptospirosis infections in Malaysia.Methodology. Data of patients admitted to various hospitals in Malaysia from 2011 to 2015 diagnosed with leptospirosis in our laboratory were obtained from their admission records. Co-infection with dengue was determined by collecting dengue serology results. Multivariate analysis and multiple logistic regression were used to differentiate features between single leptospirosis infection and confirmed LDCI.Results/Key findings. Only 602 (29.11 %) out of 2068 leptospira-positive patients were concurrently tested for dengue during their admission in which 44 (7.31 %) patients had positive non-structural protein 1 (confirmed LDCI) while 140 (23.26 %) were positive for dengue IgM (probable LDCI) with the highest number of cases recorded in high-density suburban districts. Myalgia and arthralgia were the only significant distinguishing clinical feature of LDCI while significant laboratory features were thrombocytopenia and high levels of alanine and aspartate transaminases. Only thrombocytopenia displayed a predictive value for LDCI from analysis of multiple logistic regression. Death occurred in 19 (3.16 %) patients in this dataset studied but only three (0.50 %) were attributed to LDCI.Conclusion. There is a considerable prevalence of LDCI in this country of which overlapping demographic, clinical and laboratory presentations pose diagnostic and therapeutic challenges. Efforts to raise awareness regarding LDCI, better access to diagnostic services and further prospective studies are warranted.
Synergistic effect of probe sonication and ionic liquid for extraction of phenolic acids from oak galls

Sukor NF, Jusoh R, Kamarudin NS, Abdul Halim NA, Sulaiman AZ, Abdullah SB

Ultrason Sonochem, 2020 Apr;62:104876.
PMID: 31796331 DOI: 10.1016/j.ultsonch.2019.104876

Phenolic acids of oak gall were extracted using ultrasonic-probe assisted extraction (UPAE) method in the presence of ionic liquid. It was compared with classical ultrasonic-bath assisted extraction (CUBAE) and conventional aqueous extraction (CAE) method, with and without the presence of ionic liquid. Remarkably, the UPAE method yielded two-fold higher extraction yield with the presence of ionic liquid, resulting 481.04 mg/g for gallic acids (GA) and 2287.90 mg/g for tannic acids (TA), while a decreased value of 130.36 mg/g for GA and 1556.26 mg/g for TA were resulted with the absence of ionic liquid. Intensification process resulted the highest yield of 497.34 mg/g and 2430.48 mg/g for GA and TA, respectively, extracted at temperature 50 °C with sonication intensity of 8.66 W/cm2 and 10% duty cycle, diluted in ionic liquid, 1-Butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [Bmim][Tf2N] at concentration of 0.10 M with sample-to-solvent ratio 1:10 for 8 h. Peleg's model successfully predicted the UPAE process confirming that extraction capacity is the controlling factor in extracting phenolic acids. Hence, it can be concluded that UPAE method and ionic liquid have synergistic effect as it effectively enhanced the extraction efficiency to increase the bioactive constituents yield.
Fulltext Understanding the determinants of e-wallet continuance usage intention in Malaysia

Abdul-Halim NA, Vafaei-Zadeh A, Hanifah H, Teoh AP, Nawaser K

Qual Quant, 2021 Nov 09.
PMID: 34776542 DOI: 10.1007/s11135-021-01276-7

The present research aims to investigate the determinants of e-wallet continuance usage intention in Malaysia using extending Technology Continuance Theory (TCT) via examining four variables, namely price benefit, trust, habit, and operational constraints. This paper adopts a quantitative approach to collect data with non-probability sampling using the purposive sampling technique. An online survey was conducted and a total of 379 respondents submitted their answers. The obtained results have shown that continue use of e-wallet is not affected by perceived usefulness (PU) and trust. However, there is a significant influence associated with perceived ease of use (PEU), PU, and satisfaction toward user's attitude that, in turn, substantially impacts the users' intention to continue to use e-wallet. This is one of the prior studies exploring Malaysian's intention to continue using e-wallet, using the TCT model as the research framework, and through examining four variables adopted from the literature, including price benefit, habit, trust, and operational constraints. The practical implications for the service providers and policymakers from the present findings can be used to develop strategies to gain a sustainable, competitive advantage, and promote continuous intention of e-wallet usage.
Fulltext Honeycomb and necklace signs in liver abscesses secondary to melioidosis

Ong SCL, Alemam MMM, Zakaria NA, Abdul Halim NA

BMJ Case Rep, 2017 Oct 19;2017.
PMID: 29054959 DOI: 10.1136/bcr-2017-222342

Melioidosis is endemic in Southeast Asia and tropical Australia with varying clinical features from benign skin lesions to fatal septicaemia. Imaging plays an important role in evaluation of the melioid liver abscesses. A 45-year-old man with underlying diabetes presented with fever and lethargy for 2 weeks and abdominal pain for 2 days. His liver was enlarged on examination. Blood investigations revealed mild leucocytosis and raised liver enzymes. Ultrasound showed multiple multiloculated hypoechoic lesions throughout the liver and spleen. CT of abdomen confirmed that some liver lesions were made up of asymmetric locules of varying sizes (honeycomb sign), while others had hypodense centre with small symmetric peripheral locules in radial fashion (necklace sign). Blood culture was positive for Burkholderia pseudomallei He was subsequently treated with ceftazidime for a month followed by oral trimethoprim-sulfamethoxazole for 3 months. Follow-up CT of abdomen a month after diagnosis and treatment showed resolving hepatic and splenic lesions.
Fulltext The Influence of Reaction Time on Non-Covalent Functionalisation of P3HT/MWCNT Nanocomposites

Nurazzi NM, Abdullah N, Demon SZN, Halim NA, Mohamad IS

Polymers (Basel), 2021 Jun 09;13(12).
PMID: 34207577 DOI: 10.3390/polym13121916

Non-covalent functionalisation of the carbon nanotube (CNT) sidewall through polymer wrapping is the key strategy for improving well-dispersed CNTs without persistent alteration of their electronic properties. In this work, the effect of reaction time on regioregular poly (3-hexylthiophene-2,5-diyl) (P3HT)-wrapped hydroxylated multi-walled CNT (MWCNT-OH) nanocomposites was investigated. Five different reaction times (24, 48, 72, 96, and 120 h) were conducted at room temperature in order to clearly determine the factors that influenced the quality of wrapped MWCNT-OH. Morphological analysis using Field Emission Scanning Electron Microscopic (FESEM) and High-Resolution Transmission Electron Microscope (HRTEM) analysis showed that P3HT successfully wrapped the MWCNT-OH sidewall, evidenced by the changes in the mean diameter size of the nanocomposites. Results obtained from Raman spectroscopy, X-ray Photoelectron Spectroscopy (XPS) as well as Thermogravimetric Analysis (TGA) showed a significant effect of the wrapped polymer on the CNT sidewall as the reaction time increased. Overall, the method used during the preparation of P3HT-wrapped MWCNT-OH and the presented results significantly provided a bottom-up approach to determine the effect of different reaction times on polymer wrapping to further expand this material for novel applications, especially chemical sensors.
Fulltext Intravenous parecoxib sodium as an analgesic alternative to morphine in acute trauma pain in the emergency department

Baharuddin KA, Rahman NH, Wahab SF, Halim NA, Ahmad R

Int J Emerg Med, 2014;7(1):2.
PMID: 24386899 DOI: 10.1186/1865-1380-7-2

BACKGROUND: Parecoxib sodium is the first parenteral COX-2 inhibitor used for pain management licensed for postoperative pain. However, no study has assessed the usage of parecoxib for acute traumatic pain in the emergency department (ED). The objective of this study was to investigate a potential alternative analgesic agent in the ED by determining the mean reduction of pain score between acute traumatic pain patients who were administered with intravenous (IV) parecoxib sodium versus IV morphine sulfate. The onset of perceptible analgesic effect and side effects were also evaluated.
METHODS: A randomized, double-blinded study comparing IV parecoxib 40 mg versus IV morphine at 0.10 mg/kg was conducted in adult patients presented with acute traumatic pain with numeric rating scale (NRS) of 6 or more within 6 hours of injury. Patients were randomized using a computer-generated randomization plan. Drug preparation and dispensing were performed by a pharmacist. Periodic assessment of blood pressure, pulse rate, oxygen saturation, and NRS were taken at 0, 5, 15, and 30 minute intervals after the administration of the study drug. The primary outcome was the reduction of NRS. Side effect and drug evaluation was conducted within 30 minutes of drug administration.
RESULTS: There was no statistically significant difference in the reduction of mean NRS between patients in the IV parecoxib group or IV morphine group (P = 0.095). The mean NRS for patients treated with IV morphine were 7.1 at 0 minutes, 4.5 at 5 minutes, 3.1 at 15 minutes, and 2.0 at 30 minutes. Whereas mean NRS for patients who received IV parecoxib were 7.8 at 0 minutes, 5.7 at 5 minutes, 4.7 at 15 minutes, and 3.9 at 30 minutes. The onset of perceptible analgesic effects could be seen as early as 5 minutes. Dizziness was experienced in 42.9% of patients who received IV morphine compared to none in the parecoxib group.
CONCLUSIONS: There was non-significant trend toward superiority of IV morphine over IV parecoxib. Looking at its effectiveness and the lack of opioid-related side-effects, the usage of IV parecoxib sodium may be extended further to a variety of cases in the ED.
Study site: Emergency department, Hospital Universiti Sains Malaysia (HUSM)
Fulltext Establishing H Angle Hard Tissue and H Angle Soft Tissue Norms in Skeletal Class I Malay Adult Females and the Correlation between the H Angles and Visual Perception of Laypersons

Cheong JM, A Halim NA, Mohammad N, Sivagnanam M, Mohd Ibrahim MS

Eur J Dent, 2024 Jul 16.
PMID: 39013444 DOI: 10.1055/s-0044-1787005

OBJECTIVES: This study aimed to establish the cephalometric norms of H angle soft tissue and H angle hard tissue of Malaysian Malay adult females, and to evaluate the correlation between H angles and visual perception in skeletal Class I Malay adult females.
MATERIALS AND METHODS: Eighty-five lateral cephalograms of skeletal Class I (mean ANB value = 3.15 ± 0.77) Malaysian Malay female patients aged 20 to 40 years (mean age = 28.6 ± 5.86 degrees) taken from October 2017 to December 2021 were measured for H angle soft tissue and H angle hard tissue. Twenty silhouettes were then converted from cephalometric films and were rated according to facial convexity/concavity by 20 laypersons, with re-evaluation after 2 weeks for intra- and interexaminer reliabilities.
RESULTS: The means of the H angle soft tissue and H angle hard tissue were 15.75 ± 4.16 degrees and 11.64 ± 4.71 degrees, respectively. The intraexaminer reliability test for visual perception ranged from -0.89 to 0.99 indicating poor to excellent reliability, whereas the interexaminer reliability test was 0.82 indicating good reliability. A highly statistically significant association between the H angle soft tissue and H angle hard tissue (r = 0.938; p
Immunoadsorption and plasmapheresis are equally efficacious as adjunctive therapies for severe lupus nephritis

Loo CY, Mohamed Said MS, Mohd R, Abdul Gafor AH, Saidin R, Halim NA, et al.

Transfus Apher Sci, 2010 Dec;43(3):335-40.
PMID: 21051293 DOI: 10.1016/j.transci.2010.10.003

This was a prospective randomized controlled trial to evaluate the effects of immunoadsorption (IA) versus conventional PP (PP) as adjunctive therapy in the treatment of severe lupus nephritis (LN). Of 28 patients with biopsy-proven severe LN (ISN/RPS classes III or IV ± V), 14 underwent 36 sessions of PP and the other 41 sessions of IA in addition to our center's standard LN treatment protocol. Three patients in the PP group and 2 in the IA group experienced a transient, marked drop in platelets with the second session. Except for a higher pre treatment mean SLEDAI score in the PP group 17.4 ± 2.0 vs. 13.5 ± 4.8; p = 0.009 and a serum creatinine of 163 ± 7.9 vs. 81.7 ± 10.2; p = 0.33, there were no other baseline differences. Some differences did exist between the two therapies in the immediate post-treatment phase, at 1 and 3 months. Three in IA relapsed, none of PP in third months, whereas two patients relapsed in the PP and none of IA cohorts at 6 months. However, most of these parameters did not differ by 6 months. The pre- and post-therapy SLEDAI scores remained different 12.4 ± 4.5 vs. 9 ± 4; p = 0.04 at 1 month, and at 3 month 13.5 ± 4.7 vs. 7.7 ± 1.1; p = 0.012 but not at 6 months. We conclude that IA and PP were equally well tolerated and efficacious as adjunctive therapy for severe LN.
Epidemiological Characteristics of Strongyloidiasis in Inhabitants of Indigenous Communities in Borneo Island, Malaysia

Ngui R, Halim NA, Rajoo Y, Lim YA, Ambu S, Rajoo K, et al.

Korean J Parasitol, 2016 Oct;54(5):673-678.
PMID: 27853126

Epidemiological study on strongyloidiasis in humans is currently lacking in Malaysia. Thus, a cross-sectional study was carried out to determine the prevalence of Strongyloides stercoralis infection among the inhabitants of longhouse indigenous communities in Sarawak. A single stool and blood sample were collected from each participant and subjected to microscopy, serological and molecular techniques. Five species of intestinal parasites were identified by stool microscopy. None of the stool samples were positive for S. stercoralis. However, 11% of 236 serum samples were seropositive for strongyloidiasis. Further confirmation using molecular technique on stool samples of the seropositive individuals successfully amplified 5 samples, suggesting current active infections. The prevalence was significantly higher in adult males and tended to increase with age. S. stercoralis should no longer be neglected in any intestinal parasitic survey. Combination of more than 1 diagnostic technique is necessary to increase the likelihood of estimating the 'true' prevalence of S. stercoralis.
Draft Genome Sequence of Leptospira interrogans Serovar Bataviae Strain LepIMR 22 Isolated from a Rodent in Johor, Malaysia

Amran F, Mohd Khalid MK, Mohamad S, Mat Ripen A, Ahmad N, Goris MG, et al.

Genome Announc, 2016;4(5).
PMID: 27609924 DOI: 10.1128/genomeA.00956-16

Leptospira interrogans serovar Bataviae was recently identified as one of the persistent Leptospira serovars in Malaysia. Here, we report the draft genome sequence of the L. interrogans serovar Bataviae strain LepIMR 22 isolated from kidney of a rodent in Johor, Malaysia.
Correction: Carbon nanotubes: functionalisation and their application in chemical sensors

Norizan MN, Moklis MH, Ngah Demon SZ, Halim NA, Samsuri A, Mohamad IS, et al.

RSC Adv, 2024 Mar 20;14(14):9570.
PMID: 38516155 DOI: 10.1039/d4ra90025a

[This corrects the article DOI: 10.1039/D0RA09438B.].
Fulltext Carbon nanotubes: functionalisation and their application in chemical sensors

Norizan MN, Moklis MH, Ngah Demon SZ, Halim NA, Samsuri A, Mohamad IS, et al.

RSC Adv, 2020 Nov 27;10(71):43704-43732.
PMID: 35519676 DOI: 10.1039/d0ra09438b

Carbon nanotubes (CNTs) have been recognised as a promising material in a wide range of applications, from safety to energy-related devices. However, poor solubility in aqueous and organic solvents has hindered the utilisation and applications of carbon nanotubes. As studies progressed, the methodology for CNTs dispersion was established. The current state of research in CNTs either single wall or multiwall/polymer nanocomposites has been reviewed in context with the various types of functionalisation presently employed. Functionalised CNTs have been playing an increasingly central role in the research, development, and application of carbon nanotube-based nanomaterials and systems. The extremely high surface-to-volume ratio, geometry, and hollow structure of nanomaterials are ideal for the adsorption of gas molecules. This offers great potential applications, such as in gas sensor devices working at room temperature. Particularly, the advent of CNTs has fuelled the invention of CNT-based gas sensors which are very sensitive to the surrounding environment. The presence of O2, NH3, NO2 gases and many other chemicals and molecules can either donate or accept electrons, resulting in an alteration of the overall conductivity. Such properties make CNTs ideal for nano-scale gas-sensing materials. Conductive-based devices have already been demonstrated as gas sensors. However, CNTs still have certain limitations for gas sensor application, such as a long recovery time, limited gas detection, and weakness to humidity and other gases. Therefore, the nanocomposites of interest consisting of polymer and CNTs have received a great deal of attention for gas-sensing application due to higher sensitivity over a wide range of gas concentrations at room temperature compared to only using CNTs and the polymer of interest separately.
Fulltext Application of the Logic Model to the School-Based Fit and Smart Adolescent Smoking Cessation Programme

Abdul Halim NA, Wee LH, Mohd Saat NZ, Jit Singh SJ, Siau CS, Chan CMH

Malays J Med Sci, 2022 Oct;29(5):133-145.
PMID: 36474542 DOI: 10.21315/mjms2022.29.5.14

BACKGROUND: School-based smoking cessation intervention programmes are challenging to implement and evaluate. This study aimed to explain the process of developing the Fit and Smart Adolescent Smoking Cessation Programme (FSSCP). Logic model is a visual tool that helps programme planners to create an activity action plan that suits the target group to achieve programme objectives and goals.
METHODS: This two-arm cluster-randomised controlled trial was implemented between January 2018 and November 2018. Six schools were selected using stratified random sampling, whereby students were purposively selected and invited. The criteria of inclusion to the programme were secondary school students (aged 13 years old-17 years old) who smoked conventional cigarettes (CC) and electronic cigarettes (EC).
RESULTS: A total of 422 students from six schools participated in this study. Three schools were designated as intervention (n = 250) and the other three as control schools (n = 172). Formative evaluation of participants in the FSSCP using the logic model showed that participants were satisfied with the overall programme (91.5%), were motivated to stop smoking (90.4%) and were prevented from relapse (89.2%). The quit rate at a 3-month follow-up was 41.8%.
CONCLUSION: The logic model supported the development of the programme, with details on the processes, dissemination activities, identification of barriers, evaluation criteria and outcomes provided.
Post tsunami psychological impact among survivors in Aceh and West Sumatra, Indonesia

Musa R, Draman S, Jeffrey S, Jeffrey I, Abdullah N, Halim NA, et al.

Compr Psychiatry, 2014 Jan;55 Suppl 1:S13-6.
PMID: 23318005 DOI: 10.1016/j.comppsych.2012.12.002

In 2004, the province of Aceh, Indonesia was rocked by tsunami and in September 2009, West Sumatra, Indonesia was hit by an earthquake. The aim of this study was to determine the long-term psychological impact on the residents inhabiting these regions and to identify factors associated with it.
A review on colorimetric methods for determination of organophosphate pesticides using gold and silver nanoparticles

Che Sulaiman IS, Chieng BW, Osman MJ, Ong KK, Rashid JIA, Wan Yunus WMZ, et al.

Mikrochim Acta, 2020 01 15;187(2):131.
PMID: 31940088 DOI: 10.1007/s00604-019-3893-8

This review (with 99 refs.) summarizes the progress that has been made in colorimetric (i.e. spectrophotometric) determination of organophosphate pesticides (OPPs) using gold and silver nanoparticles (NPs). Following an introduction into the field, a first large section covers the types and functions of organophosphate pesticides. Methods for colorimetric (spectrophotometric) measurements including RGB techniques are discussed next. A further section covers the characteristic features of gold and silver-based NPs. Syntheses and modifications of metal NPs are covered in section 5. This is followed by overviews on enzyme inhibition-based assays, aptamer-based assays and chemical (non-enzymatic) assays, and a discussion of specific features of colorimetric assays. Several Tables are presented that give an overview on the wealth of methods and materials. A concluding section addresses current challenges and discusses potential future trends and opportunities. Graphical abstractSchematic representation of organophosphate pesticide determinations based on aggregation of nanoparticles (particular silver or gold nanoparticles). This leads to a color change which can be determined visually and monitored by a red shift in the absorption spectrum.
Fulltext Comparative Study on Extraction of Cellulose Fiber from Rice Straw Waste from Chemo-Mechanical and Pulping Method

Razali NAM, Mohd Sohaimi R, Othman RNIR, Abdullah N, Demon SZN, Jasmani L, et al.

Polymers (Basel), 2022 Jan 19;14(3).
PMID: 35160377 DOI: 10.3390/polym14030387

Inspired by nature, cellulose extracted from plant wastes has been explored, due to its great potential as an alternative for synthetic fiber and filler that contributes to structural performance. The drive of this study was to extract, treat, and evaluate the characteristics of rice straw (RS) (Oryza sativa L.) cellulose as a biodegradable reinforcement to be utilized in polymer base materials. Two routes of extraction and treatment were performed via the pulping (Route 1) and chemo-mechanical methods (Route 2), in order to discover comparative characteristics of the synthesized cellulose fiber. Comprehensive characterization of RS cellulose was carried out to determine crystallinity, surface morphology, and chemical bonding properties, using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and Fourier transform infra-red (FTIR), respectively. The XRD test results showed that the crystallinity index (CI) of cellulose powder (CP) decreased after the surface modification treatment, Route 2, from 64.50 to 50.10% CI for modified cellulose powder (MCP), due to the surface alteration of cellulose structure. From Route 1, the crystallinity of the fibers decreased up to 33.5% (dissolve cellulose, DC) after the pulp went through the surface modification and dissolution processes, resulting from the transformation of cellulose phase into para-crystalline structure. FESEM micrographs displayed a significant reduction of raw RS diameter from 7.78 µm to 3.34 µm (treated by Route 1) and 1.06 µm (treated by Route 2). The extracted and treated cellulose via both routes, which was considerably dominated by cellulose II because of the high percentage of alkaline used, include the dissolve cellulose (DC). The dissolution process, using NMMO solvent, was performed on the pulp fiber produced by Route 1. The fiber change from cellulose I to cellulose II after undergoes the process. Thus, the dissolution process maintains cellulose II but turned the pulp to the cellulose solution. The acquired characteristics of cellulose from RS waste, extracted by the employed methods, have a considerably greater potential for further application in numerous industries. It was concluded that the great achievement of extracted RS is obtained the nanosized fibers after surface modification treatment, which is very useful for filler in structural composite applications.

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