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Fulltext Survey dataset on occupational stress, job satisfaction, and job performance among male fertility patients

Majid NFH, Muhamad S, Kusairi S, Ramli R

Data Brief, 2024 Apr;53:110152.
PMID: 38375144 DOI: 10.1016/j.dib.2024.110152

This article presents data on occupational stress, job satisfaction, and job performance among male fertility patients. The data were collected from 11 November 2021 until 30 October 2022. A quantitative research approach was employed, involving a questionnaire development and survey. A sample of 309 was selected, using simple random sampling, from the pool of male patients that had undergone seminal fluid analysis (SFA) and received treatment from four private fertility clinics in Malaysia. Respondents were asked to give their consent by signing a consent form, for ethical research purposes. The questionnaire asked respondents about their demographics, sperm quality, occupational stress, job satisfaction, and job performance. The data could help other researchers to develop research on management issue in the context of male fertility, as well as organisations to maintain the health and welfare of their employees.
Fulltext Elucidating the daily foraging activity pattern of Oecophylla smaragdina to minimize bite nuisances in Asia large agro-system plantations

Exélis MP, Ramli R, Abdul Latif SA, Idris AH, Clemente-Orta G, Kermorvant C

Heliyon, 2024 Feb 29;10(4):e26105.
PMID: 38434038 DOI: 10.1016/j.heliyon.2024.e26105

Oecophylla smaragdina F., the Asian weaver ant, is one of the oil palm plantation's (Elaeis guineensis) potential predators, for the invasive bagworm species Metisa plana Walker, but this ant is a nuisance species that irritates plantation workers with their sharp bites. Here we assess the foraging activities (FA) of O. smaragdina's major workers, identify its inactive times and the existence of supervision, a novelty for social insects. Between 2018 and 2022, the pattern of trunk foraging activity was used as a mitigation measure. The relationship between trunk FA and air temperature (AT), relative humidity (RH), air pressure (AP), and rainfall interception (RI) was also investigated. Our results showed that, O. smaragdina is a strictly diurnal ant species, has little to no crepuscular activity, and stopped foraging during darkness. Moreover, veteran bigger workers systematically acted as supervisors by monitoring trails, intercepting, and bringing back to nests smaller individuals during heat peaks. In relation to population size relative abundance, all colonies displayed greater intensity during the warmest daily periods with higher mean forager density among the bigger colony, regardless of the dry-rainy intervals corresponded to minimal activity from late scotophase to early photophase and showed a bimodal pattern. Thus, forager activity peaked between 1100-1530 h and 1745-1845 h, and an average two-fold daily sudden decrease in intensity between 1620 and 1650 h as a partial cut-off period (first report). Furthermore, foraging activity, AT, AP showed a significant positive correlation while RH was negative. Finally, we found that from the base palm trunks, defensive territorial layers extended to 5 m on average with different spatial configurations indicating greater foraging density within the first 2 m. Our study shows O. smaragdina daily low activity periods, before 1000 h, being the most suitable to avoid forager attacks to facilitate pruning and harvesting tasks.
Fulltext Comparison between hCG and GnRH Agonist for Ovulation Trigger in GnRH Antagonist In-Vitro Fertilization Cycles in a Tertiary Hospital in Malaysia: An observational study

Aziz NA, Ibrahim A, Ramli R, Yaacob N, Rahman SNA, Ismail EHE, et al.

JBRA Assist Reprod, 2024 Feb 26;28(1):21-26.
PMID: 38224580 DOI: 10.5935/1518-0557.20230066

OBJECTIVE: hCG is commonly used as an ovulation trigger in IVF. Its usage is associated with OHSS. GnRH agonist is an alternative to hCG and is associated with reduced incidence of OHSS. This study compared the cycle outcomes of GnRH agonists with hCG as an ovulation trigger in IVF cycles.
METHODS: The medical notes of 209 IVF cycles receiving GnRH agonist and hCG as ovulation trigger over 18 months were reviewed in this retrospective study. The number and quality of mature oocytes, the number and quality of embryos, pregnancy rates, and outcomes were compared using Independent T-test or One-way ANOVA for normal distribution. The Mann-Whitney test or Kruskal-Wallis test was used for not normally distributed. p<0.05 was considered statistically significant.
RESULTS: The cycle outcomes of 107 GnRH agonist-trigger and 102 hCG-trigger were compared. The MII oocytes retrieved and 2PN count was significantly higher in the GnRH agonist trigger group (p<0.001). Clinical pregnancy rate and ongoing pregnancy were higher in the GnRH agonist trigger group but were not statistically significant. The GnRH agonist trigger group was associated with low OHSS than the hCG trigger group (n=2(1.9%) and n=12(11.8%) respectively, p=0.004).
CONCLUSION: GnRH agonist trigger is an option as a final maturation trigger in high-responder women undergoing IVF or ICSI cycles.
Fulltext Actuators and transmission mechanisms in rehabilitation lower limb exoskeletons: a review

Aliman N, Ramli R, Amiri MS

Biomed Tech (Berl), 2024 Jan 31.
PMID: 38295350 DOI: 10.1515/bmt-2022-0262

Research has shown that rehabilitation lower limb exoskeletons (RLLEs) are effective tools for improving recovery or regaining lower limb function. This device interacts with the limbs of patients. Thus, actuators and power transmission mechanisms are the key factors in determining smooth human‒machine interaction and comfort in physical therapy activities. A multitude of distinct technologies have been proposed. However, we questioned which consideration point in actuator selection and power transmission mechanisms are used for RLLE. A review of the technical characteristics and status of advanced RLLE designs is discussed. We review actuator selection for RLLE devices. Furthermore, the power transmission mechanisms over the years within each of the RLLE devices are presented. The development issues and possible research directions related to actuators and power transmission mechanisms are provided. Most RLLEs are still in the research phase, and only a few have been commercialized. The aim of this paper is to provide researchers with useful information for investigating technological progress and highlight the latest technological choices in RLLE development.
Bicornuate bicollis uterus with right cervical stenosis and ipsilateral renal agenesis

Nik Mhd Nor NS, Ahmad Khairuddin SND, Ramli R

BMJ Case Rep, 2024 Jan 09;17(1).
PMID: 38199665 DOI: 10.1136/bcr-2023-259175
Fulltext Redescription, molecular characterisation and Wolbachia endosymbionts of Mansonella (Tupainema) dunni (Mullin & Orihel, 1972) (Spirurida: Onchocercidae) from the common treeshrew Tupaia glis Diard & Duvaucel (Mammalia: Scandentia) in Peninsular Malaysia

Mat Udin AS, Uni S, Rodrigues J, Martin C, Junker K, Agatsuma T, et al.

Curr Res Parasitol Vector Borne Dis, 2024;5:100154.
PMID: 38193019 DOI: 10.1016/j.crpvbd.2023.100154

The genus Mansonella Faust, 1929 includes 29 species, mainly parasites of platyrrhine monkeys in South America and anthropoid apes in Africa. In Malaysia, Mansonella (Tupainema) dunni (Mullin & Orihel, 1972) was described from the common treeshrew Tupaia glis Diard & Duvaucel (Scandentia). In a recent classification of the genus Mansonella, seven subgenera were proposed, with M. (Tup.) dunni as a monotypic species in the subgenus Tupainema. In this study, we collected new material of M. (Tup.) dunni from common treeshrews in Peninsular Malaysia and redescribed the morphological features of this species. We found that M. (Tup.) dunni differs from M. (Cutifilaria) perforata Uni et al., 2004 from sika deer Cervus nippon (Cetartiodactyla) in Japan, with regards to morphological features and predilection sites in their respective hosts. Based on multi-locus sequence analyses, we examined the molecular phylogeny of M. (Tup.) dunni and its Wolbachia genotype. Species of the genus Mansonella grouped monophyletically in clade ONC5 and M. (Tup.) dunni was placed in the most derived position within this genus. Mansonella (Tup.) dunni was closely related to M. (M.) ozzardi (Manson, 1897) from humans in Central and South America, and most distant from M. (C.) perforata. The calculated p-distances between the cox1 gene sequences for M. (Tup.) dunni and its congeners were 13.09% for M. (M.) ozzardi and 15.6-16.15% for M. (C.) perforata. The molecular phylogeny of Mansonella spp. thus corroborates their morphological differences. We determined that M. (Tup.) dunni harbours Wolbachia endosymbionts of the supergroup F genotype, in keeping with all other Mansonella species screened to date.
Fulltext Recurrent Temporal Infections: The Link to Systemic Lupus Erythematosus

Shuhardi SA, Mohamed Said MS, Kew TY, Ramli R

Am J Case Rep, 2023 Dec 29;24:e942163.
PMID: 38155491 DOI: 10.12659/AJCR.942163

BACKGROUND Systemic lupus erythematosus (SLE) is an autoimmune disease with diverse manifestations. The involvement of the musculoskeletal system is very common, and infection is one of the manifestations, which can involve any part of the body. We report a case of a middle-aged woman with recurrent episodes of infection of her left temple. CASE REPORT A 51-year old woman was referred to our clinic following failures to eradicate infection on her left temple for 9 months. Examination revealed facial asymmetry, with diffuse non-tender swelling involving her left temple area, which extended to her cheek. Computed tomography and magnetic resonance imaging (MRI) showed a periosteal reaction of the zygomatic bone. Left temporalis muscle thickening and residual osteomyelitis of the zygomatic bone were also shown by MRI. In view of the unresolved infection with incision and drainage and antibiotics, further blood investigations led to the discovery of SLE. The antinuclear antibody and anti-double-stranded DNA were positive. In addition, low nephelometry markers, C3 (26.7 mg/dL) and C4 (8.24 mg/dL), were observed. This patient was treated with 200 mg of oral hydrochloroquine once daily and 5 mg of oral prednisolone once daily. After 6 months of treatment, the infection subsided, and the structures involved showed remarkable healing. The patient is still taking the same dose and frequency of both drugs at the present time. CONCLUSIONS Temporalis pyomyositis and osteomyelitis of the zygomatic bone could be manifestation of SLE disease; however, the involvement of infection cannot be ruled out.
Tuberculosis (TB) of the genital tract presenting with secondary amenorrhoea

Abdul Mulalek N, Wan Abas WR, Muhammad Tamyez F, Ramli R

BMJ Case Rep, 2023 Dec 18;16(12).
PMID: 38110342 DOI: 10.1136/bcr-2023-258548
Acute lower limb ischaemia secondary to aortic compression from uterine fibroid

Nawawi SH, Wan Ibrahim WZ, Yahya MM, Ramli R

BMJ Case Rep, 2023 Aug 17;16(8).
PMID: 37591622 DOI: 10.1136/bcr-2022-253129

A woman in her early 50s with uncontrolled diabetes mellitus and a huge uterine fibroid presented to the emergency department with diabetic ketoacidosis and bilateral acute lower limb ischaemia. Vascular and advanced imaging studies confirmed distal aortic compression by a huge uterine fibroid, resulting in extensive lower limb arterial thrombosis. After resuscitation, the patient underwent emergency hysterectomy, thromboembolectomy and amputation of the right leg. She remained critically ill and died of fulminant sepsis and multiorgan failure 10 days later. This case reports the effects of external vascular compression by a large pelvic mass.
MyWSL: Malaysian words sign language dataset

Johari RT, Ramli R, Zulkoffli Z, Saibani N

Data Brief, 2023 Aug;49:109338.
PMID: 37600131 DOI: 10.1016/j.dib.2023.109338

Deaf and hard-of-hearing individuals use sign language as a means of communication. However, those around them, especially family members like the children of deaf adults, may face communication challenges if they are unfamiliar with sign language. This issue has prompted numerous researchers to conduct studies on sign language translation and recognition. However, there is currently no publicly available dataset specifically for Malaysian sign language. This article introduces an image dataset of the Malaysian Sign Language (MySL) hand gestures used in everyday situations. The dataset, named MyWSL2023, comprises 3,500 images of ten static Malaysian sign language words collected from five participants (two males and three females) aged between 20 and 21 years old. The data collection took place indoors under normal lighting conditions. The MyWSL2023 dataset, which has been made freely accessible to all researchers, serves as a valuable resource for not only investigating and developing automated systems for hearing-impaired and deaf individuals but also gesture and sign language recognition using vision-based methods. The dataset can be accessed for free at https://data.mendeley.com/datasets/zvk55p7ktd.
Alpha-amyrin as an anti-biofilm agent against methicillin-resistant and vancomycin-intermediate Staphylococcus aureus

Chung PY, Loh PLN, Neoh HM, Ramli R

Heliyon, 2023 Jul;9(7):e17892.
PMID: 37456062 DOI: 10.1016/j.heliyon.2023.e17892

Staphylococcus aureus has caused life-threatening infections and developed resistance against conventional antimicrobials, posing a significant threat to human health worldwide. Biofilms that surround the bacteria cells act as a protective layer, allowing cells inside the biofilm to be resistant to external stresses such as antimicrobials. Therefore, biofilms further complicate treatment available for infections caused by multi-drug resistant Staphylococcus aureus. A previous study on alpha-amyrin (AM), derived from ursane, was reported to significantly reduce the biomass and inhibit the metabolic activity of reference strain methicillin-resistant and methicillin-sensitive S. aureus (MRSA and MSSA, respectively). In this study, the antibiofilm activity of AM was extended to include clinical isolates of MSSA and MRSA, and laboratory-generated vancomycin-intermediate S. aureus (VISA) collected from University Kebangsaan Malaysia Medical Center (PPUKM) and Universiti Kebangsaan Malaysia Medical Molecular Biology Institute (UMBI). Pre-formed biofilms of biofilm-forming isolates identified from the Congo Red Agar (CRA) assay were then exposed to AM, vancomycin and oxacillin, and evaluated using the crystal violet and resazurin assays. The results showed that AM reduced the biofilm biomass of three isolates of MSSA, eight isolates of MRSA and four isolates of VISA but increased the metabolic activity in certain MSSA, MRSA and VISA isolates, indicating AM may possess biofilm reduction effects but not bactericidal effects. Based on these findings, AM could be further studied and developed as a potential therapeutic agent for chronic S. aureus infections.
Fulltext Application of neurotransmitters and dental stem cells for pulp regeneration: A review

Ramli H, Yusop N, Ramli R, Berahim Z, Peiris R, Ghani N

Saudi Dent J, 2023 Jul;35(5):387-394.
PMID: 37520592 DOI: 10.1016/j.sdentj.2023.05.004

INTRODUCTION: Although there have been many studies on stem cells, few have investigated how neurotransmitters and stem cell proliferation interact to regenerate dental pulp. Dental pulp regeneration is an innovative procedure for reviving dental pulp, if feasible for the entire tooth. Upon tooth injury, activated platelets release serotonin and dopamine in bulk to mobilize dental pulp stem cells to mediate natural dental repair. This has induced research on the role of neurotransmitters in increasing the proliferation rate of stem cells. This review also covers prospective future treatments for dental pulp regeneration.
METHODS: A literature search was performed via PubMed and ScienceDirect from 2001 to 2022, using the keywords "neurotransmitter," "stem cell," "tooth regeneration," "tooth repair," "regenerative dentistry," and "dental pulp." Different inclusion/exclusion criteria were used, and the search was restricted to English articles.
RESULTS: Nine publications reporting neurotransmitter interactions with stem cells for tooth and pulp regeneration were selected.
CONCLUSION: Neurotransmitters were found to interact with dental stem cells. Evidence pointing to neurotransmitters as a factor in the increased proliferation of stem cells was found. This review thus gives hope for tooth pulp regeneration and repair.
Fulltext Identification of Potential Biomarkers and Small Molecule Drugs for Bisphosphonate-Related Osteonecrosis of the Jaw (BRONJ): An Integrated Bioinformatics Study Using Big Data

Balachandran K, Ramli R, Karsani SA, Abdul Rahman M

Int J Mol Sci, 2023 May 11;24(10).
PMID: 37239981 DOI: 10.3390/ijms24108635

This study aimed to identify potential molecular mechanisms and therapeutic targets for bisphosphonate-related osteonecrosis of the jaw (BRONJ), a rare but serious side effect of bisphosphonate therapy. This study analyzed a microarray dataset (GSE7116) of multiple myeloma patients with BRONJ (n = 11) and controls (n = 10), and performed gene ontology, a pathway enrichment analysis, and a protein-protein interaction network analysis. A total of 1481 differentially expressed genes were identified, including 381 upregulated and 1100 downregulated genes, with enriched functions and pathways related to apoptosis, RNA splicing, signaling pathways, and lipid metabolism. Seven hub genes (FN1, TNF, JUN, STAT3, ACTB, GAPDH, and PTPRC) were also identified using the cytoHubba plugin in Cytoscape. This study further screened small-molecule drugs using CMap and verified the results using molecular docking methods. This study identified 3-(5-(4-(Cyclopentyloxy)-2-hydroxybenzoyl)-2-((3-hydroxybenzo[d]isoxazol-6-yl) methoxy) phenyl) propanoic acid as a potential drug treatment and prognostic marker for BRONJ. The findings of this study provide reliable molecular insight for biomarker validation and potential drug development for the screening, diagnosis, and treatment of BRONJ. Further research is needed to validate these findings and develop an effective biomarker for BRONJ.
Diagnostic value of serum and tissue eosinophil in diagnosis of asthma among patients with chronic rhinosinusitis

Che Mat CMH, Md Shukri N, Mohamad S, Tuan Sharif SE, Ramli R, Jais MH, et al.

Eur Arch Otorhinolaryngol, 2023 May;280(5):2283-2291.
PMID: 36401099 DOI: 10.1007/s00405-022-07746-4

BACKGROUND: Chronic rhinosinusitis (CRS) is one of the most common chronic inflammatory diseases of sinonasal mucosa. Asthma among CRS patients is often underdiagnosed which makes the management of CRS more challenging. Therefore, using serum and tissue eosinophil as an indicator and predictor of asthma in CRS patients is vital for further preventing recurrent and increasing the effectiveness of treatment for CRS.
OBJECTIVE: To determine the association and diagnostic ability of serum and tissue eosinophils in the diagnosis of asthma among CRS patients.
METHODS: A cross-sectional study was conducted involving 24 CRS patients with asthma and without asthma, respectively, from the Otorhinolaryngology clinic of two tertiary hospitals located on the East Coast of Peninsular Malaysia. Serum and tissue eosinophils (obtained from nasal polyp) levels between both groups were compared. Association between serum and tissue eosinophils with asthma was evaluated using logistic regression analysis, adjusting for important sociodemographic characteristics. The diagnostic ability of serum and tissue eosinophil was then evaluated by assessing the receiver operating characteristic curve.
RESULTS: A total of 48 CRS patients with a mean [SD] age of 47.50 [14.99] years were included. Patients with asthma had significantly higher serum [0.48 vs 0.35 × 109/L] and tissue eosinophil [100 vs 8.5 per HPF] levels. Tissue eosinophils were found to be an independent predictor of asthma with adjusted OR 1.05, p 0.375 × 109/L and tissue eosinophil > 58 per HPF.
Fulltext Perception Regarding the NICE Guideline on Antibiotic Prophylaxis against Infective Endocarditis Following Dental Procedures: A Cross-Sectional Study

Mohd Yunus SS, Nabil S, Rashdi MF, Nazimi AJ, Nordin R, Tan HL, et al.

Antibiotics (Basel), 2023 Apr 02;12(4).
PMID: 37107058 DOI: 10.3390/antibiotics12040696

This study explores the opinions of Malaysian clinical specialists on the antibiotic prophylaxis against infective endocarditis (IE) as described in the 2008 National Institute for Health and Care Excellence (NICE) guideline. This cross-sectional study was performed from September 2017 to March 2019. The self-administered questionnaire comprised two sections: background information of the specialists and their opinions on the NICE guideline. The questionnaire was distributed to 794 potential participants, and 277 responded (response rate of 34.9%). In general, 49.8% of the respondents believed that clinicians should adhere to the guideline, although the majority of oral and maxillofacial surgeons (54.5%) actually disagreed with this view. The dental procedures that were perceived as presented moderate-to-high risk for IE were minor surgery for an impacted tooth with a recent episode of infection, dental implant surgery, periodontal surgery and dental extraction in patients with poor oral hygiene. The cardiac conditions that were strongly recommended for antibiotic prophylaxis were severe mitral valve stenosis or regurgitation and previous IE. Less than half of Malaysian clinical specialists agreed with the changes in the 2008 NICE guideline, contributing to their insistence that antibiotic prophylaxis is still needed for high-risk cardiac conditions and selected invasive dental procedures.
Healthcare resources, organisational support and practice in asthma in six public health clinics in Malaysia

Hussein N, Ramli R, Liew SM, Hanafi NS, Lee PY, Cheong AT, et al.

NPJ Prim Care Respir Med, 2023 Mar 27;33(1):13.
PMID: 36973274 DOI: 10.1038/s41533-023-00337-8

Asthma, a common chronic respiratory illness is mostly managed in primary care. We aimed to determine healthcare resources, organisational support, and doctors' practice in managing asthma in a Malaysian primary care setting. A total of six public health clinics participated. We found four clinics had dedicated asthma services. There was only one clinic which had a tracing defaulter system. Long-term controller medications were available in all clinics, but not adequately provided. Resources, educational materials, and equipment for asthma management were present, though restricted in number and not placed in main locations of the clinic. To diagnose asthma, most doctors used clinical judgement and peak flow metre measurements with reversibility test. Although spirometry is recommended to diagnose asthma, it was less practiced, being inaccessible and unskilled in using as the main reasons. Most doctors reported providing asthma self-management; asthma action plan, but for only half of the patients that they encountered. In conclusion, there is still room for improvement in the provision of clinic resources and support for asthma care. Utilising peak flow metre measurement and reversibility test suggest practical alternative in low resource for spirometry. Reinforcing education on asthma action plan is vital to ensure optimal asthma care.
Barriers to and Facilitators of Asthma Care For Malaysian Hajj Pilgrims: A Qualitative Study

Ramli R, Hanafi NS, Hussein N, Lee PY, Shariff Ghazali S, Cheong AT, et al.

Asia Pac J Public Health, 2023 Feb 28.
PMID: 36852891 DOI: 10.1177/10105395231158684

Asthma exacerbations are among the commonest reasons for hospitalizations in Malaysian pilgrims during the Hajj. We interviewed 21 stakeholders involved in the pre-Hajj health examination at 14 primary care clinics, to explore their perceptions on barriers to and facilitators of asthma care for Hajj pilgrims. The disadvantages of the short time frame and centralized organization of the pre-Hajj health examinations were viewed as compromising clinicians' level of competencies in asthma care, which could potentially be enhanced through more training, audit, and supervision by specialists. Longer time frame to permit sufficient disease control, provision of care by a dedicated asthma team, asthma registry to support continuous care, more resources of long-acting β-agonist/inhaled corticosteroid, and provision of influenza and pneumococcal vaccines at no cost were the perceived facilitators. Delivery of asthma education, especially the asthma action plan, should be tailored to the level of the pilgrim's health literacy and facilitated by educational resources, family engagement, and regular health briefing.
Antimicrobial, antiadhesive, and antibiofilm actions of rhamnolipids on ESKAPE pathogens

Firdose A, Chong NHH, Ramli R, Aqma WS

Lett Appl Microbiol, 2023 Feb 16;76(2).
PMID: 36702549 DOI: 10.1093/lambio/ovad013

The aim of this study was to test the antimicrobial, antiadhesive, and antibiofilm activities of a rhamnolipid extracted from Pseudomonas aeruginosa UKMP14T previously isolated from oil-contaminated soil in Malaysia against ESKAPE (i.e. multidrug resistant) pathogens. Zones of inhibition in an agar well diffusion assay were observed at 50 µg mL-1 concentrations of rhamnolipid for all the ESKAPE bacteria. The MIC and MBC values ranged between 7.81-62.5 µg mL-1 and 31.25-1000 µg mL-1, respectively. Percent killing was recorded to be >90% except for Klebsiella pneumoniae (86.84%). Furthermore, antiadhesion studies showed that there was 76% hindrance in attachment of Enterococcus faecium and 91% in Acinetobacter baumannii at 4 × MIC. The highest inhibition in adhesion was found at 4 × MIC, which was 46% for Ac. baumannii and 62% for Enterococcus faecium. Finally, the antibiofilm capability of the rhamnolipid was determined, which ranged between 25%-76% in Ac. baumannii and 35%-88% in Enterococcus faecium. To the best of our knowledge, this is the first study to include research on antimicrobial, antiadhesive and antibiofilm activities of rhamnolipid from the local isolate Ps. aeruginosa UKMP14T against ESKAPE bacteria. Obtained results suggest that this rhamnolipid can be exploited commercially for the production of novel antibiotics.
Fulltext Dorsal root ganglia control nociceptive input to the central nervous system

Hao H, Ramli R, Wang C, Liu C, Shah S, Mullen P, et al.

PLoS Biol, 2023 Jan;21(1):e3001958.
PMID: 36603052 DOI: 10.1371/journal.pbio.3001958

Accumulating observations suggest that peripheral somatosensory ganglia may regulate nociceptive transmission, yet direct evidence is sparse. Here, in experiments on rats and mice, we show that the peripheral afferent nociceptive information undergoes dynamic filtering within the dorsal root ganglion (DRG) and suggest that this filtering occurs at the axonal bifurcations (t-junctions). Using synchronous in vivo electrophysiological recordings from the peripheral and central processes of sensory neurons (in the spinal nerve and dorsal root), ganglionic transplantation of GABAergic progenitor cells, and optogenetics, we demonstrate existence of tonic and dynamic filtering of action potentials traveling through the DRG. Filtering induced by focal application of GABA or optogenetic GABA release from the DRG-transplanted GABAergic progenitor cells was specific to nociceptive fibers. Light-sheet imaging and computer modeling demonstrated that, compared to other somatosensory fiber types, nociceptors have shorter stem axons, making somatic control over t-junctional filtering more efficient. Optogenetically induced GABA release within DRG from the transplanted GABAergic cells enhanced filtering and alleviated hypersensitivity to noxious stimulation produced by chronic inflammation and neuropathic injury in vivo. These findings support "gating" of pain information by DRGs and suggest new therapeutic approaches for pain relief.
Fulltext Investigation of inerter-based suspension systems for heavy vehicles

Soong MF, Ramli R, Saifizul AA, Goh KY, Long SX

PLoS One, 2023;18(1):e0280290.
PMID: 36662679 DOI: 10.1371/journal.pone.0280290

The inerter is a two-terminal component that can be added to the spring-and-damper configuration of a suspension system. It has the property that the force exerted is proportional to the relative acceleration at its terminals. Studies have demonstrated the inerter's benefit of providing superior vibration isolation when it is used in the vehicle suspension of passenger cars. However, similar benefit on another common vehicle class on the roads, namely heavy vehicles, remain to be shown, as these vehicles have vastly different parameter values than passenger cars. This study is an investigation on the performance improvement brought by an inerter in the suspension of common heavy vehicles. In the study, the parameter values of a truck and a bus were adopted in the quarter vehicle model with two different spring-damper-inerter configurations (parallel and serial inerter), and the improvements in vibration isolation and road holding capability were determined by optimization of inertance. Results show that the inerter is similarly effective in providing the said improvements when implemented on heavy vehicles instead of on passenger cars, judging from reductions in sprung mass acceleration and dynamic tire load. It is also observed that the performance benefit is associated with larger optimum inertance than that for passenger cars. Overall, the inerter has been shown to be beneficial in the parallel and serial configurations, both of which are common and can be practically implemented in the suspension of heavy vehicles.

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