Browse publications by year: 2023

  1. Veeramohan R, Zamani AI, Azizan KA, Goh HH, Aizat WM, Razak MFA, et al.
    PLoS One, 2023;18(3):e0283147.
    PMID: 36943850 DOI: 10.1371/journal.pone.0283147
    The fresh leaves of Mitragyna speciosa (Korth.) Havil. have been traditionally consumed for centuries in Southeast Asia for its healing properties. Although the alkaloids of M. speciosa have been studied since the 1920s, comparative and systematic studies of metabolite composition based on different leaf maturity levels are still lacking. This study assessed the secondary metabolite composition in two different leaf stages (young and mature) of M. speciosa, using an untargeted liquid chromatography-electrospray ionisation-time-of-flight-mass spectrometry (LC-ESI-TOF-MS) metabolite profiling. The results revealed 86 putatively annotated metabolite features (RT:m/z value) comprising 63 alkaloids, 10 flavonoids, 6 terpenoids, 3 phenylpropanoids, and 1 of each carboxylic acid, glucoside, phenol, and phenolic aldehyde. The alkaloid features were further categorised into 14 subclasses, i.e., the most abundant class of secondary metabolites identified. As per previous reports, indole alkaloids are the most abundant alkaloid subclass in M. speciosa. The result of multivariate analysis (MVA) using principal component analysis (PCA) showed a clear separation of 92.8% between the young and mature leaf samples, indicating a high variance in metabolite levels between them. Akuammidine, alstonine, tryptamine, and yohimbine were tentatively identified among the many new alkaloids reported in this study, depicting the diverse biological activities of M. speciosa. Besides delving into the knowledge of metabolite distribution in different leaf stages, these findings have extended the current alkaloid repository of M. speciosa for a better understanding of its pharmaceutical potential.
    MeSH terms: Plant Extracts/chemistry; Plant Leaves/metabolism; Indole Alkaloids/analysis; Secologanin Tryptamine Alkaloids*; Metabolomics
  2. Ngan TT, Ramanathan K, Saleh MRBM, Schliemann D, Ibrahim Tamin NSB, Su TT, et al.
    BMJ Open, 2023 Mar 21;13(3):e066925.
    PMID: 36944471 DOI: 10.1136/bmjopen-2022-066925
    OBJECTIVES: The 2020-2022 research project 'Colorectal Cancer Screening Intervention for Malaysia' (CRC-SIM) evaluated the implementation of a home-based CRC screening pilot in Segamat District. This budget impact analysis (BIA) assessed the expected changes in health expenditure of the Malaysian Ministry of Health budget in the scenario where the pilot programme was implemented nationwide vs current opportunistic screening.

    DESIGN: Budget impact analysis. Assumptions and costs in the opportunistic and novel CRC screening scenarios were derived from a previous evaluation of opportunistic CRC screening in community health clinics across Malaysia and the CRC-SIM research project, respectively.

    SETTING: National level (with supplement analysis for district level). The BIA was conducted from the viewpoint of the federal government and estimated the annual financial impact over a period of 5 years.

    RESULTS: The total annual cost of the current practice of opportunistic screening was RM1 584 321 (~I$1 099 460) of which 80% (RM1 274 690 or ~I$884 587) was expended on the provision of opportunistic CRC to adults who availed of the service. Regarding the implementation of national CRC screening programme, the net budget impact in the first year was estimated to be RM107 631 959 (~I$74 692 546) and to reach RM148 485 812 (~I$103 043 589) in the fifth year based on an assumed increased uptake of 5% annually. The costs were calculated to be sensitive to the probability of adults who were contactable, eligible and agreeable to participating in the programme.

    CONCLUSIONS: Results from the BIA provided direct and explicit estimates of the budget changes to when implementing a population-based national CRC screening programme to aid decision making by health services planners and commissioners in Malaysia about whether such programme is affordable within given their budget constraint. The study also illustrates the use and value of the BIA approach in low-income and middle-income countries and resource-constrained settings.

    MeSH terms: Budgets; Cost-Benefit Analysis; Humans; Malaysia; Mass Screening/methods
  3. Xiong J, Domnic Jacob GA, Xiong JG
    Am J Health Behav, 2023 Feb 28;47(1):165-172.
    PMID: 36945091 DOI: 10.5993/AJHB.47.1.17
    Objectives: In this study, we analyzed negative online public opinion in tertiary hospitals and evaluated corresponding risk by applying the Kaiser Model. Methods: Through data and expert group discussion, combined with the hospital's actual negative online public opinion management, we determined the opinions posing higher risk. The hospital's risk questionnaire for negative opinion was designed based on the Kaiser Model. The whole hospital staff was then trained and investigated. An Excel worksheet was used for statistical analysis and risk calculation.Results: According to the ranking of risk value, the top 5 negative online public opinions were drug supply and demand, in-hospital parking, handling of public health emergencies, the service attitude of hospital guidance staff, and interpretation of medical insurance policies. Conclusion: The hospital needs to revise and improve the emergency response plan for negative online public opinion based on the analysis results and reports of opinion risks. This is helpful for strengthening hospital-level emergency training, improving the hospital's ability to manage negative opinion risks, and promoting the hospital to become passive about negative online public opinion.
    MeSH terms: Humans; Public Health; Public Opinion*; Surveys and Questionnaires; Risk Management*; Tertiary Care Centers
  4. Than WW, Binti Pg Baharuddin DM, Hossain Parash MT, Mra A
    Cureus, 2023 Feb;15(2):e35092.
    PMID: 36945266 DOI: 10.7759/cureus.35092
    Term abdominal pregnancy is a sporadic ectopic pregnancy associated with high maternal and perinatal morbidity and mortality. As symptoms are non-specific and resemble those of other ectopic pregnancies, early diagnosis is the major challenge in poor health setups. A 24-year-old primigravida at 38 weeks gestation was planned to undergo a cesarean section for the transverse lie. Abdominal pregnancy was accidentally discovered during the cesarean section, and a healthy, normal baby boy was delivered. The placenta was attached to the greater omentum, so its removal required omentectomy without compromising the blood supply to the bowels. Both patient and her baby boy were discharged on the seventh day without complications. No congenital anomalies were detected in the baby. In a term abdominal pregnancy, the most significant challenges are the control of bleeding and the decision on placenta removal, followed by prompt delivery of the fetus. Therefore, along with the gynecologist, the availability of trained personnel, such as anesthetists, pediatricians, and general surgeons, is necessary for a successful management outcome.
  5. Zakaria L
    Plant Dis, 2023 Mar;107(3):603-615.
    PMID: 35819350 DOI: 10.1094/PDIS-02-22-0358-FE
    Basal stem rot of oil palm caused by Ganoderma boninense is the most serious disease of oil palm in Malaysia, Indonesia, and other oil-palm-producing countries. Economic losses caused by the disease can be up to USD500 million a year. For many years, basal stem rot was found to infect older palm trees of more than 25 to 30 years in age. Only in the 1950s, the disease began to appear in much younger palm trees, 10 to 15 years old, and, in the last decade or so, palm trees as young as 1 year were infected by the disease. The highest incidence occurs in coastal areas of Southeast Asia but the disease has now infected oil palm in inland areas, mainly oil palm planted in peat soils. Disease incidence is also high in areas previously growing coconut or forest. Basal stem rot infection and spread occur through root-to-root contact, and basidiospores that colonize the roots also play a role. In the early stages of infection by G. boninense, the pathogen behaves as a biotroph and later as a necrotroph, secreting cell-wall-degrading enzymes and triggering host defense responses. Genes, gene products, and metabolic pathways involved in oil palm defense mechanisms against G. boninense have been identified and these metabolites have the potential to be used as markers for early detection of the disease. Integrated disease management used to control basal stem rot includes cultural practices, chemical control, and application of biocontrol agents or fertilizers. Early detection tools have also been developed that could assist in management of basal stem rot infections. Development of resistant or tolerant oil palm is still at an early stage; therefore, the existing integrated disease management practices remain the most appropriate methods for managing basal stem rot of oil palm.
    MeSH terms: Indonesia; Incidence; Arecaceae*
  6. Tilawatu N, Tan Chor Lip H
    ANZ J Surg, 2023 Mar;93(3):750-751.
    PMID: 35950571 DOI: 10.1111/ans.17976
    MeSH terms: Abdomen; Caustics*; Child; Eating; Humans; Intestine, Small; Electric Power Supplies
  7. Agarwal A, Cannarella R, Saleh R, Boitrelle F, Gül M, Toprak T, et al.
    World J Mens Health, 2023 Apr;41(2):289-310.
    PMID: 36326166 DOI: 10.5534/wjmh.220142
    PURPOSE: Despite the significant role of varicocele in the pathogenesis of male infertility, the impact of varicocele repair (VR) on conventional semen parameters remains controversial. Only a few systematic reviews and meta-analyses (SRMAs) have evaluated the impact of VR on sperm concentration, total motility, and progressive motility, mostly using a before-after analytic approach. No SRMA to date has evaluated the change in conventional semen parameters after VR compared to untreated controls. This study aimed to evaluate the effect of VR on conventional semen parameters in infertile patients with clinical varicocele compared to untreated controls.

    MATERIALS AND METHODS: A literature search was performed using Scopus, PubMed, Embase, and Cochrane databases following the Population Intervention Comparison Outcome (PICOS) model (Population: infertile patients with clinical varicocele; Intervention: VR [any technique]; Comparison: infertile patients with clinical varicocele that were untreated; Outcome: sperm concentration, sperm total count, progressive sperm motility, total sperm motility, sperm morphology, and semen volume; Study type: randomized controlled trials and observational studies).

    RESULTS: A total of 1,632 abstracts were initially assessed for eligibility. Sixteen studies were finally included with a total of 2,420 infertile men with clinical varicocele (1,424 patients treated with VR vs. 996 untreated controls). The analysis showed significantly improved post-operative semen parameters in patients compared to controls with regards to sperm concentration (standardized mean difference [SMD] 1.739; 95% CI 1.129 to 2.349; p<0.001; I²=97.6%), total sperm count (SMD 1.894; 95% CI 0.566 to 3.222; p<0.05; I²=97.8%), progressive sperm motility (SMD 3.301; 95% CI 2.164 to 4.437; p<0.01; I²=98.5%), total sperm motility (SMD 0.887; 95% CI 0.036 to 1.738; p=0.04; I²=97.3%) and normal sperm morphology (SMD 1.673; 95% CI 0.876 to 2.470; p<0.05; I²=98.5%). All the outcomes showed a high inter-study heterogeneity, but the sensitivity analysis showed that no study was sensitive enough to change these results. Publication bias was present only in the analysis of the sperm concentration and progressive motility. No significant difference was found for the semen volume (SMD 0.313; 95% CI -0.242 to 0.868; I²=89.7%).

    CONCLUSIONS: This study provides a high level of evidence in favor of a positive effect of VR to improve conventional semen parameters in infertile men with clinical varicocele. To the best of our knowledge, this is the first SRMA to compare changes in conventional semen parameters after VR with changes in parameters of a control group over the same period. This is in contrast to other SRMAs which have compared semen parameters before and after VR, without reference to a control group. Our findings strengthen the available evidence and have a potential to upgrade professional societies' practice recommendations favoring VR to improve conventional semen parameters in infertile men.

  8. Nagendrababu V, Duncan HF, Fouad AF, Kirkevang LL, Parashos P, Pigg M, et al.
    Int Endod J, 2023 Feb 27.
    PMID: 36851874 DOI: 10.1111/iej.13909
    Observational studies play a critical role in evaluating the prevalence and incidence of conditions or diseases in populations as well as in defining the benefits and potential hazards of health-related interventions. There are currently no reporting guidelines for observational studies in the field of Endodontics. The Preferred Reporting Items for study Designs in Endodontology (PRIDE) team has developed and published new reporting guidelines for observational-based studies called the 'Preferred Reporting items for OBservational studies in Endodontics (PROBE) 2023' guidelines. The PROBE 2023 guidelines were developed exclusively for the speciality of Endodontics by integrating and adapting the 'STrengthening the Reporting of OBservational studies in Epidemiology (STROBE)' checklist and the 'Clinical and Laboratory Images in Publications (CLIP)' principles. The recommendations of the Guidance for Developers of Health Research Reporting Guidelines were adhered to throughout the process of developing the guidelines. The purpose of this document is to serve as a guide for authors by providing an explanation for each of the items in the PROBE 2023 checklist along with relevant examples from the literature. The document also offers advice to authors on how they can address each item in their manuscript before submission to a journal. The PROBE 2023 checklist is freely accessible and downloadable from the PRIDE website (http://pride-endodonticguidelines.org/probe/).
  9. Zuleta D, Arellano G, McMahon SM, Aguilar S, Bunyavejchewin S, Castaño N, et al.
    Glob Chang Biol, 2023 Jun;29(12):3409-3420.
    PMID: 36938951 DOI: 10.1111/gcb.16687
    Accurate estimates of forest biomass stocks and fluxes are needed to quantify global carbon budgets and assess the response of forests to climate change. However, most forest inventories consider tree mortality as the only aboveground biomass (AGB) loss without accounting for losses via damage to living trees: branchfall, trunk breakage, and wood decay. Here, we use ~151,000 annual records of tree survival and structural completeness to compare AGB loss via damage to living trees to total AGB loss (mortality + damage) in seven tropical forests widely distributed across environmental conditions. We find that 42% (3.62 Mg ha-1  year-1 ; 95% confidence interval [CI] 2.36-5.25) of total AGB loss (8.72 Mg ha-1  year-1 ; CI 5.57-12.86) is due to damage to living trees. Total AGB loss was highly variable among forests, but these differences were mainly caused by site variability in damage-related AGB losses rather than by mortality-related AGB losses. We show that conventional forest inventories overestimate stand-level AGB stocks by 4% (1%-17% range across forests) because assume structurally complete trees, underestimate total AGB loss by 29% (6%-57% range across forests) due to overlooked damage-related AGB losses, and overestimate AGB loss via mortality by 22% (7%-80% range across forests) because of the assumption that trees are undamaged before dying. Our results indicate that forest carbon fluxes are higher than previously thought. Damage on living trees is an underappreciated component of the forest carbon cycle that is likely to become even more important as the frequency and severity of forest disturbances increase.
    MeSH terms: Carbon; Trees*; Tropical Climate*; Biomass; Forests
  10. Wong CHM, Xu N, Lim J, Feng KK, Chan WKW, Chan MTY, et al.
    Prostate, 2023 Jun;83(8):801-808.
    PMID: 36938957 DOI: 10.1002/pros.24519
    BACKGROUND: Androgen deprivation therapy (ADT) use in prostate cancer (PCa) has seen a rising trend. We investigated the relationship between ADT and adverse changes in metabolic parameters in an Asian population.

    METHODS: This is an international prospective multicenter single-arm cohort yielded from the real-life experience of ADT in Asia (READT) registry. Consecutive ADT-naïve patients diagnosed of PCa and started on ADT were prospectively recruited from 2016 and analyzed. Baseline patient characteristics, PCa disease status, and metabolic parameters were documented. Patients were followed up at 6-month interval for up to 5 years. Metabolic parameters including body weight, lipid profiles, and glycemic profiles were recorded and analyzed.

    RESULTS: 589 patients were eligible for analysis. ADT was associated with adverse glycemic profiles, being notable at 6 months upon ADT initiation and persisted beyond 1 year. Comparing to baseline, fasting glucose level and hemoglobin A1c level increased by 4.8% (p 

    MeSH terms: Androgen Antagonists/adverse effects; Androgens; Asia/epidemiology; Body Weight; Humans; Lipids; Male; Prospective Studies
  11. Rakib MRJ, Al Nahian S, Madadi R, Haider SMB, De-la-Torre GE, Walker TR, et al.
    Environ Sci Process Impacts, 2023 May 25;25(5):929-940.
    PMID: 36939043 DOI: 10.1039/d3em00014a
    Microplastic (MP) pollution is a major global issue that poses serious threats to aquatic organisms. Although research on MP pollution has been extensive, the relationship between MPs and water quality parameters in estuarine water systems is unclear. This work studied the spatiotemporal distribution and characteristics of MPs in the Karnaphuli River estuary, Bangladesh. MP abundance was calculated by towing with a plankton net (300 μm mesh size) at three river gradients (up-, mid- and downstream) and the association between physicochemical parameters of water (temperature, pH, salinity, electrical conductivity, total dissolved solids, and dissolved oxygen) and MP distribution patterns was also investigated. Mean MP abundance in water was higher during the wet season (April) (4.33 ± 2.45 items per m3) compared to the dry season (September) (3.65 ± 2.54 items per m3). In descending order, the highest MP abundance was observed downstream (6.60 items per m3) > midstream (3.15 items per m3) > upstream (2.22 items per m3). pH during the wet season (April) and temperature during the dry season (September) were key physicochemical parameters that correlated with river MP abundance (r = -0.74 and 0.74 respectively). Indicating that if the Karnaphuli River water has low pH or high temperature, there is likely to be high MPs present in the water. Most MP particles were film-shaped, white in color, and 1-5 mm in size. Of the six polymers detected, polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), and cellulose were predominant, comprising roughly 17-19% each. These results can be used to model MP transport in the freshwater ecosystem of the Karnaphuli River estuary in Bangladesh to help develop future mitigation strategies.
    MeSH terms: Environmental Monitoring; Plastics; Ecosystem; Estuaries
  12. Christopher SS, Thakur AK, Hazra SK, Sharshir SW, Pandey AK, Rahman S, et al.
    PMID: 36940023 DOI: 10.1007/s11356-023-26399-2
    The aim of this research was to develop a model for a solar refrigeration system (SRS) that utilizes an External Compound Parabolic Collector and a thermal energy storage system (TESS) for solar water heating in Chennai, India. The system parameters were optimized using TRNSYS software by varying factors such as collector area, mass flow rate of heat transfer fluid, and storage system volume and height. The resulting optimized system was found to meet 80% of hot water requirements for the application on an annual basis, with an annual collector energy efficiency of 58% and an annual TESS exergy efficiency of 64% for a discharge period of 6 h per day. In addition, the thermal performance of 3.5 kW SRS was studied by connecting it to an optimized solar water heating system (SWHS). The system was found to generate an average cooling energy of 12.26 MJ/h annually, with a coefficient of performance of 0.59. By demonstrating the ability to efficiently generate both hot water and cooling energy, the results of this study indicate the potential for utilizing a SWHS in combination with STST and SRS. The optimization of system parameters and the use of exergy analysis provide valuable insights into the thermal behavior and performance of the system, which can inform future designs and improve the overall efficiency of similar systems.
  13. Mamat R, Rashid RA, Sim MS, Ibrahim B, Wahab S, Ahmad A
    J Psychoactive Drugs, 2023 Mar 20.
    PMID: 36940284 DOI: 10.1080/02791072.2023.2190331
    ATS dependence in Malaysia is growing tremendously across multiracial Malaysian groups, increasing concerns among public health experts and the community. This study highlighted the chronicity of ATS dependence and factors associated with ATS use. Interviewer-administered questionnaires were administered using ASSIST 3.0. A total of N = 327 multiracial people who use ATS were enrolled in this study. The study findings show that 190/327 (58.1%) respondents were ATS dependent. Malays reported the highest number of ATS-dependent (55.8%), followed by Bajau (21.6%) and Kadazan-Dusun (16.8%) ethnic. Across all races, three factors were significantly associated with the ATS dependence: respondents who had a lifetime history of needle sharing aOR = 0.023 (95% CI: 0.003, 0.183) and a lifetime history of heroin use aOR = 0.192 (95% CI: 0.093, 0.396) were at a reduced odd of ATS dependent. Meanwhile, being married reduced the likelihood of becoming dependent on ATS with aOR = 0.378 (95% CI: 0.206, 0.693) compared to being single or divorced. This study revealed that the use of ATS among multiracial Malaysians is alarmingly high, including those in detention centers. Comprehensive harm reduction strategies are urgently needed to prevent the spreading of infectious diseases and other negative health consequences associated with ATS use.
  14. Mubarak E, Kaur S, Min MTK, Hughes MT, Rushton CH, Ali J
    J Clin Ethics, 2023;34(1):51-57.
    PMID: 36940355 DOI: 10.1086/723317
    AbstractThe COVID-19 pandemic has inspired numerous opportunities for telehealth implementation to meet diverse healthcare needs, including the use of virtual communication platforms to facilitate the growth of and access to clinical ethics consultation (CEC) services across the globe. Here we discuss the conceptualization and implementation of two different virtual CEC services that arose during the COVID-19 pandemic: the Clinical Ethics Malaysia COVID-19 Consultation Service and the Johns Hopkins Hospital Ethics Committee and Consultation Service. A common strength experienced by both platforms during virtual delivery included improved ability for local practitioners to address consultation needs for patient populations otherwise unable to access CEC services in their respective locations. Additionally, virtual platforms allowed for enhanced collaboration and sharing of expertise among ethics consultants. Both contexts encountered numerous challenges related to patient care delivery during the pandemic. The use of virtual technologies resulted in decreased personalization of patient-provider communication. We discuss these challenges with respect to contextual differences specific to each service and setting, including differences in CEC needs, sociocultural norms, resource availability, populations served, consultation service visibility, healthcare infrastructure, and funding disparities. Through lessons learned from a health system in the United States and a national service in Malaysia, we provide key recommendations for health practitioners and clinical ethics consultants to leverage virtual communication platforms to mitigate existing inequities in patient care delivery and increase capacity for CEC globally.
    MeSH terms: Humans; Malaysia; United States; Telemedicine; Ethics, Clinical*; Ethics Consultation*; Pandemics
  15. Xie D, Zhang H, Wei H, Lin L, Wang D, Wang M
    Aquat Toxicol, 2023 May;258:106497.
    PMID: 36940520 DOI: 10.1016/j.aquatox.2023.106497
    The continuous fragmentation of plastics and release of synthetic nanoplastics from products have been aggravating nanoplastic pollution in the marine ecosystem. The carrier role of nanoplastics may increase the bioavailability and toxicity effects of toxic metals, e.g., mercury (Hg), which is of growing concern. Here, the copepod Tigriopus japonicus was exposed to polystyrene nanoplastics (PS NPs) and Hg (alone or combined) at environmental realistic concentrations for three generations (F0-F2). Then, Hg accumulation, physiological endpoints, and transcriptome were analyzed. The results showed that the copepod's reproduction was significantly inhibited under PS NPs or Hg exposure. The presence of PS NPs caused significantly higher Hg accumulation, lower survival, and lower offspring production in copepods relative to Hg exposure, suggesting an increased threat to the copepod's survivorship and health. From the molecular perspective, combined PS NPs and Hg caused a graver effect on the DNA replication, cell cycle, and reproduction pathways relative to Hg exposure, linking to lower levels of survivorship and reproduction. Taken together, this study provides an early warning of nanoplastic pollution for the marine ecosystem not only because of their adverse effect per se but also their carrier role for increasing Hg bioaccumulation and toxicity in copepods.
    MeSH terms: Animals; Polystyrenes/toxicity; Ecosystem; Copepoda*
  16. Vijayanand M, Ramakrishnan A, Subramanian R, Issac PK, Nasr M, Khoo KS, et al.
    Environ Res, 2023 Mar 20;227:115716.
    PMID: 36940816 DOI: 10.1016/j.envres.2023.115716
    Polycyclic aromatic hydrocarbons (PAHs) are considered a major class of organic contaminants or pollutants, which are poisonous, mutagenic, genotoxic, and/or carcinogenic. Due to their ubiquitous occurrence and recalcitrance, PAHs-related pollution possesses significant public health and environmental concerns. Increasing the understanding of PAHs' negative impacts on ecosystems and human health has encouraged more researchers to focus on eliminating these pollutants from the environment. Nutrients available in the aqueous phase, the amount and type of microbes in the culture, and the PAHs' nature and molecular characteristics are the common factors influencing the microbial breakdown of PAHs. In recent decades, microbial community analyses, biochemical pathways, enzyme systems, gene organization, and genetic regulation related to PAH degradation have been intensively researched. Although xenobiotic-degrading microbes have a lot of potential for restoring the damaged ecosystems in a cost-effective and efficient manner, their role and strength to eliminate the refractory PAH compounds using innovative technologies are still to be explored. Recent analytical biochemistry and genetically engineered technologies have aided in improving the effectiveness of PAHs' breakdown by microorganisms, creating and developing advanced bioremediation techniques. Optimizing the key characteristics like the adsorption, bioavailability, and mass transfer of PAH boosts the microorganisms' bioremediation performance, especially in the natural aquatic water bodies. This review's primary goal is to provide an understanding of recent information about how PAHs are degraded and/or transformed in the aquatic environment by halophilic archaea, bacteria, algae, and fungi. Furthermore, the removal mechanisms of PAH in the marine/aquatic environment are discussed in terms of the recent systemic advancements in microbial degradation methodologies. The review outputs would assist in facilitating the development of new insights into PAH bioremediation.
  17. Kim H, Liu Y, Lu K, Chang CS, Sung D, Akl M, et al.
    Nat Nanotechnol, 2023 May;18(5):464-470.
    PMID: 36941360 DOI: 10.1038/s41565-023-01340-3
    Layer transfer techniques have been extensively explored for semiconductor device fabrication as a path to reduce costs and to form heterogeneously integrated devices. These techniques entail isolating epitaxial layers from an expensive donor wafer to form freestanding membranes. However, current layer transfer processes are still low-throughput and too expensive to be commercially suitable. Here we report a high-throughput layer transfer technique that can produce multiple compound semiconductor membranes from a single wafer. We directly grow two-dimensional (2D) materials on III-N and III-V substrates using epitaxy tools, which enables a scheme comprised of multiple alternating layers of 2D materials and epilayers that can be formed by a single growth run. Each epilayer in the multistack structure is then harvested by layer-by-layer mechanical exfoliation, producing multiple freestanding membranes from a single wafer without involving time-consuming processes such as sacrificial layer etching or wafer polishing. Moreover, atomic-precision exfoliation at the 2D interface allows for the recycling of the wafers for subsequent membrane production, with the potential for greatly reducing the manufacturing cost.
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