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Background: Quality of life (QOL) is associated with mortality in dialysis patients. However, the impact of QOL index or score on elderly patients undergoing maintenance dialysis is unclear. We analyzed the relationship between QOL domains and survival in elderly end-stage renal disease (ESRD) patients on dialysis., Methods: We included 492 incident ESRD patients aged ≥65 years from a Korean nationwide prospective cohort study who were assessed for QOL with a follow-up duration of 67.3 ± 34.6 months after dialysis initiation. Their QOL was evaluated using the Kidney Disease Quality of Life (KDQOL) instrument, and the effect of each QOL domain on mortality was analyzed. Multivariable Cox regression analysis was performed to identify independent risk factors for death after adjusting for confounding factors., Results: Low physical component summary (PCS) and Short Form-36 score were significantly associated with low survival rate ( P  < .001 and P  = .017, respectively), whereas the mental component summary and ESRD-targeted item scores were not correlated with survival rate. Multivariable Cox regression analysis confirmed that only a high PCS score was associated with better survival (hazard ratio 0.71; 95% confidence interval 0.52-0.97; P  = .031). Linear regression analysis revealed that age, sex, modified Charlson comorbidity index, albumin and intact parathyroid hormone were associated with PCS. Among the PCS items, only the physical functioning score was significantly associated with mortality ( P  = .017)., Conclusion: PCS was an independent risk factor for death in elderly ESRD patients. A higher physical functioning score was associated with a better outcome, suggesting the importance of physical condition in elderly dialysis patients., Competing Interests: The authors declare no competing interests, (© The Author(s) 2024. Published by Oxford University Press on behalf of the ERA.)

In recent years, gene therapy has been made possible with the success of nucleic acid drugs against sepsis and its related organ dysfunction. Therapeutics based on nucleic acids such as small interfering RNAs (siRNAs), microRNAs (miRNAs), messenger RNAs (mRNAs), and plasmid DNAs (pDNAs) guarantee to treat previously undruggable diseases. The advantage of nucleic acid-based therapy against sepsis lies in the development of nanocarriers, achieving targeted and controlled gene delivery for improved efficacy with minimal adverse effects. Entrapment into nanocarriers also ameliorates the poor cellular uptake of naked nucleic acids. In this study, we discuss the current state of the art in nanoparticles for nucleic acid delivery to treat hyperinflammation and apoptosis associated with sepsis. The optimized design of the nanoparticles through physicochemical property modification and ligand conjugation can target specific organs-such as lung, heart, kidney, and liver-to mitigate multiple sepsis-associated organ injuries. This review highlights the nanomaterials designed for fabricating the anti-sepsis nanosystems, their physicochemical characterization, the mechanisms of nucleic acid-based therapy in working against sepsis, and the potential for promoting the therapeutic efficiency of the nucleic acids. The current investigations associated with nanoparticulate nucleic acid application in sepsis management are summarized in this paper. Noteworthily, the potential application of nanotherapeutic nucleic acids allows for a novel strategy to treat sepsis. Further clinical studies are required to confirm the findings in cell- and animal-based experiments. The capability of large-scale production and reproducibility of nanoparticle products are also critical for commercialization. It is expected that numerous anti-sepsis possibilities will be investigated for nucleic acid-based nanotherapeutics in the future., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Signal transduction through G protein-coupled receptors (GPCRs) has been a major focus in cell biology for decades. Numerous disorders are associated with GPCRs that utilize G i proteins to inhibit adenylyl cyclase (AC) as well as regulate other effectors. Several early studies have successfully defined the AC-interacting domains of several members of Gα i by measuring the loss of activity upon homologous replacements of putative regions of constitutive active Gα i mutants. However, whether such findings can indeed be translated into the context of a receptor-activated Gα i have not been rigorously verified. To address this issue, an array of known and new chimeric mutations was introduced into GTPase-deficient Q204L (QL) and R178C (RC) mutants of Gα i1 , followed by examinations on their ability to inhibit AC. Surprisingly, most chimeras failed to abolish the constitutive activity brought on by the QL mutation, while some were able to eliminate the inhibitory activity of RC mutants. Receptor-mediated inhibition of AC was similarly observed in the same chimeric constructs harbouring the pertussis toxin (PTX)-resistant C351I mutation. Moreover, RC-bearing loss-of-function chimeras appeared to be hyper-deactivated by endogenous RGS protein. Molecular docking revealed a potential interaction between AC and the α3/β5 loop of Gα i1 . Subsequent cAMP assays support a cooperative action of the α3/β5 loop, the α4 helix, and the α4/β6 loop in mediating AC inhibition by Gα i1-i3 . Our results unveiled a notable functional divergence between constitutively active mutants and receptor-activated Gα i1 to inhibit AC, and identified a previously unknown AC-interacting domain of Gα i subunits. These results collectively provide valuable insights on the mechanism of AC inhibition in the cellular environment., (© 2024. The Author(s).)

Dual immunoglobulin domain-containing cell adhesion molecule (DICAM) is a type I transmembrane protein that presents in various cells including renal tubular cells. This study evaluated the expression and protective role of DICAM in renal tubular cell injury. HK-2 cells were incubated and treated with lipopolysaccharide (LPS, 30 μg/mL) or hydrogen peroxide (H 2 O 2 , 100 μM) for 24 h. To investigate the effect of the gene silencing of DICAM, small interfering RNA of DICAM was used. Additionally, to explain its role in cellular response to injury, DICAM was overexpressed using an adenoviral vector. DICAM protein expression levels significantly increased following treatment with LPS or H 2 O 2 in HK-2 cells. In response to oxidative stress, DICAM showed an earlier increase (2-4 h following treatment) than neutrophil gelatinase-associated lipocalin (NGAL) (24 h following treatment). DICAM gene silencing increased the protein expression of inflammation-related markers, including IL-1β, TNF-α, NOX4, integrin β1, and integrin β3, in H 2 O 2 -induced HK-2 cell injury. Likewise, in the LPS-induced HK-2 cell injury, DICAM knockdown led to a decrease in occludin levels and an increase in integrin β3, IL-1β, and IL-6 levels. Furthermore, DICAM overexpression followed by LPS-induced HK-2 cell injury resulted in an increase in occludin levels and a decrease in integrin β1, integrin β3, TNF-α, IL-1β, and IL-6 levels, suggesting an alleviating effect on inflammatory responses. DICAM was elevated in the early stage of regular tubular cell injury and may protect against renal tubular injury through its anti-inflammatory properties. DICAM has a potential as an early diagnostic marker and therapeutic target for renal cell injury.

Objectives: Obesity and type 2 diabetes mellitus (T2DM) are growing health concerns. Since 2005, Student Health Service (SHS) and Hong Kong Paediatric Society formulated a protocol on urine glucose screening (UGS) for early diagnosis of T2DM in students with obesity in Hong Kong. This study reviews students with T2DM captured by this screening program and compare the data with the Hong Kong Children Diabetes Registry (HKCDR) database, to see if the UGS program facilitates early diagnosis of T2DM., Methods: Students between the ages of 10-18 years old with age- and sex-specific body mass index (BMI) >97th percentile who attended SHS between the school years from 2005/06 to 2017/18 were recruited for UGS. Those tested positive for random urine glucose underwent diagnostic testing for T2DM according to ADA guidelines. Demographic data and investigatory results from UGS and HKCDR within the same time period were compared., Results: A total of 216,526 students completed UGS in the said period; 415 (0.19 %) students were tested positive for urine glucose of which 121 students were diagnosed with T2DM. UGS picked up 23 % of the newly diagnosed T2DM cases. When compared to the HKCDR database, students diagnosed via UGS were significantly younger, less obese, and had fewer diabetic related complications. The negative predictive value of UGS is high and can effectively rule out T2DM., Conclusions: Urine glucose screening is an inexpensive and simple test that allows for early diagnosis of T2DM among obese school students. Other methods including POCT HbA 1c can be explored to improve program effectiveness., (© 2023 Walter de Gruyter GmbH, Berlin/Boston.)

Excessive exposure to sunlight, especially UV irradiation, causes skin photodamage. Sunscreens, such as TiO 2 and ZnO, can potentially prevent UV via scattering, reflection, and absorption. Topical antioxidants are another means of skin photoprotection. Developing nanoparticles for sunscreens and antioxidants is recommended for photoaging prevention and treatment as it can improve uncomfortable skin appearance, stability, penetration, and safety. This study reviewed the effects of nano-sized sunscreens and antioxidants on skin photoprevention by examining published studies and articles from PubMed, Scopus, and Google Scholar, which explore the topics of skin photoaging, skin senescence, UV radiation, keratinocyte, dermal fibroblast, sunscreen, antioxidant, and nanoparticle. The researchers of this study also summarized the nano-based UV filters and therapeutics for mitigating skin photoaging. The skin photodamage mechanisms are presented, followed by the introduction of current skin photoaging treatment. The different nanoparticle types used for topical delivery were also explored in this study. This is followed by the mechanisms of how nanoparticles improve the UV filters and antioxidant performance. Lastly, recent investigations were reviewed on nanoparticulate sunscreens and antioxidants in skin photoaging management. Sunscreens and antioxidants for topical application have different concepts. Topical antioxidants are ideal for permeating into the skin to exhibit free radical scavenging activity, while UV filters are prescribed to remain on the skin surface without absorption to exert the UV-blocking effect without causing toxicity. The nanoparticle design strategy for meeting the different needs of sunscreens and antioxidants is also explored in this study. Although the benefits of using nanoparticles for alleviating photodamage are well-established, more animal-based and clinical studies are necessary., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Competing Interests: None declared.

Background: Incidence of depression increases in patients with end-stage kidney disease (ESKD). We evaluated the association between depression and mortality among older patients with ESKD, which has not been studied previously., Methods: This nationwide prospective cohort study included 487 patients with ESKD aged >65 years, who were categorized into minimal, mild-to-moderate, and severe depression groups based on their Beck Depression Inventory-II (BDI-II) scores. Predisposing factors for high BDI-II scores and the association between the scores and survival were analyzed., Results: The severe depression group showed a higher modified Charlson comorbidity index value and lower serum albumin, phosphate, and uric acid levels than the other depression groups. The Kaplan-Meier curve revealed a significantly lower survival in the severe depression group than in the minimal and mild-to-moderate depression groups (p = 0.011). Multivariate Cox regression analysis confirmed that severe depression was an independent risk factor for mortality in the study cohort (hazard ratio, 1.39; 95% confidence interval, 1.01-1.91; p = 0.041). Additionally, BDI-II scores were associated with modified Charlson comorbidity index (p = 0.009) and serum albumin level (p = 0.004) in multivariate linear regression. Among the three depressive symptoms, higher somatic symptom scores were associated with increased mortality., Conclusion: Severe depression among older patients with ESKD increases mortality compared with minimal or mild-to-moderate depression, and patients with concomitant somatic symptoms require careful management of their comorbidities and nutritional status.

Rationale: The World Health Organization defines a perivascular epithelioid cell tumor (PEComa) as a mesenchymal neoplasia composed of perivascular epithelioid cells with characteristic morphological and immunohistochemical features. Although PEComas have the potential to behave in a malignant fashion, malignant PEComas are extremely rare., Patient Concerns: An 83-year-old man visited our clinic presented with palpable, painless, and movable mass in the right knee area., Diagnoses: Malignant PEComa was diagnosed by incisional biopsy. No metastases was confirmed by radiologic imaging including PET/CT, magnetic resonance imaging, high resolution computed tomography., Interventions: We performed wide excision of the mass and used an anterolateral thigh free flap to reconstruct the defect on the right knee., Outcomes: The permanent histopathology showed malignant PEComa was totally resected. The flap which was performed to cover the defect was survived and the patient discharge without any complications., Lessons: PEComa can metastasize to various anatomical regions. Although there is no established standardized treatment, radical resection is still considered the cornerstone of treatment. Rapid and appropriate defect coverage is important to improve the patient's prognosis., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2023 the Author(s). Published by Wolters Kluwer Health, Inc.)

Adhesion-type G protein-coupled receptors (aGPCRs) have long resisted approaches to resolve the structural details of their heptahelical transmembrane (7TM) domains. Single-particle cryogenic electron microscopy (cryo-EM) has recently produced aGPCR 7TM domain structures for ADGRD1, ADGRG1, ADGRG2, ADGRG3, ADGRG4, ADGRG5, ADGRF1, and ADGRL3. We review the unique properties, including the position and conformation of their activating tethered agonist (TA) and signaling motifs within the 7TM bundle, that the novel structures have helped to identify. We also discuss questions that the kaleidoscope of novel aGPCR 7TM domain structures have left unanswered. These concern the relative positions, orientations, and interactions of the 7TM and GPCR autoproteolysis-inducing (GAIN) domains with one another. Clarifying their interplay remains an important goal of future structural studies on aGPCRs., Competing Interests: Declaration of interests The authors declare no conflicts of interest., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

About 95% of cervical cancers worldwide are caused by human papillomavirus (HPV). Cervical cancer is preventable and curable if it is detected and treated early. We reviewed the latest national cervical cancer indicators, and barriers to HPV vaccination and cervical cancer screening in 21 Asian National Cancer Centers Alliance (ANCCA) member countries. Half (n = 11, 52%) of the countries have introduced HPV vaccination for girls as part of their national vaccination programme, three countries reported coverage of over 90%. Most ANCCA member countries have cervical cancer screening programmes, only five countries reported screening uptake of over 50%. The barriers to HPV vaccination coverage and cervical cancer screening participation have been identified. Ensuring health service accessibility and affordability for women, addressing sociocultural barriers, and strengthening the healthcare system and continuum of care are essential to increase HPV vaccination and cervical cancer screening coverage., Competing Interests: The authors have no conflicts of interest to declare., (© 2023 Published by Elsevier Ltd.)

Background: Free tissue transfer is the preferred method of reconstructing head and neck defects, with a success rate of approximately 95%. Although flap failure is uncommon, it has a major impact on patient morbidity and diminishes quality of life, making it is important to investigate the causes of flap failure., Methods: This retrospective chart review analyzed patients who underwent free tissue transfer during head and neck reconstruction at a single institution between 2016 and 2021., Results: During the study period, 58 patients underwent 60 free flap procedures. Revision surgery was needed in 14 patients. Subsequent free flap surgery was performed in one patient, and three free flaps (5%) could not be salvaged. Cardiovascular disease was significantly associated with flap failure, and venous congestion (thrombosis) was the most common reason for revision surgery., Conclusion: Cardiovascular disease clearly emerged as a factor related to the failure of free flap surgery, and this issue warrants particular attention in patients for whom free tissue transfer is planned.

Introduction: This brief report describes how a family medicine residency practice (FMRP) leveraged a resident-led quality improvement project and a grant-funded Addiction Integrated Care Team (AICT) to initiate an office-based opioid treatment (OBOT) program to provide medications for opioid use disorder during the COVID-19 pandemic., Method: In 2020, the practice experienced four disruptors that shifted motivation for practice development: (a) The COVID-19 pandemic demanded rapid change in primary care processes/staffing, including pivoting to telehealth/remote practice. (b) The practice's transition to a federally qualified community health center model meant a shift in organizational priorities that required offering OBOT services. (c) External grant resources became available through the AICT program to support practice core for OBOT, and 10 implementation strategies were utilized. (d) A resident champion implemented an OBOT quality improvement project., Results: These efforts resulted in the practice offering the OBOT program and 18 patients receiving OBOT from January 2020 to February 2021, with 10 of 18 patients engaged for 12 months or longer. Further, the cumulative adoption and reach from January 2020 through September 2022 was 15 faculty and 14 residents becoming prescribers and 101 patients served within the OBOT program, respectively., Discussion: FMRPs striving for significant practice transformation, such as implementing an OBOT program during a pandemic, may benefit from synergistic guidance and resources including established theory, strategies from the implementation science literature, and resident-led quality improvement efforts. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Objectives: To study the relationship between the 2019 EULAR/ACR classification criteria and organ damage in patients with systemic lupus erythematosus (SLE)., Methods: Patients involved in a cross-sectional validation study of the EULAR/ACR criteria and judged by a panel of rheumatologists to be clinical SLE were studied. Those who fulfilled the EULAR/ACR criteria at their last clinic visit were stratified into 2 groups based on a cutoff score of 20. The last SLE International Collaborating Clinic (SLICC) Organ Damage Index (SDI) was compared between these two groups. Relationship among the domains of the EULAR/ACR criteria and SDI in all patients was studied by using Spearman's rank correlation., Results: A total of 562 SLE patients were studied (93.6% women; age 36.5 ± 14.1 years; follow-up duration 11.6 ± 6.6 years). The mean and median EULAR/ACR criteria scores in those who fulfilled the EULAR/ACR criteria ( N = 542) were 24.6 ± 7.3 and 24 (interquartile range 19-30), respectively. A total of 392 patients had EULAR/ACR scores of ≥20 (group 1), and 150 patients had scores of 10-19 (group 2). Group 1 patients had significantly higher prevalence of fever, alopecia, oral ulcers, acute lupus skin lesions, arthritis, serositis, seizure, hemolytic anemia, leukopenia, and renal disease and so were the anti-dsDNA, anti-Sm, antiphospholipid antibodies, and low complement state. Organ damage (SDI score of ≥1) occurred in 232 (42.8%) patients. Patients in group 1 had significantly higher SDI scores in the renal, cardiovascular, dermatological, and gonadal domains than group 2. The renal, neuropsychiatric, and antiphospholipid antibody domain scores of the EULAR/ACR criteria correlated positively with the total SDI. The renal domain of the EULAR/ACR criteria had the strongest correlation with renal damage (Rho 0.30; p < 0.001). Patients who scored 10 points in the renal domain had significantly higher renal damage score than those scored 8 points or 4 points. Gonadal damage score was also significantly more common in the 10-point than in the 8-point group., Conclusion: In addition to disease classification, the EULAR/ACR SLE criteria may have value in predicting prognosis.

Background: Mycophenolate mofetil exhibits pharmacologic mechanisms different from calcineurin inhibitors. Therefore, the dose of calcineurin inhibitors can be reduced along with side effects for effective immunosuppression. We aimed to evaluate the efficacy and safety of tacrolimus and corticosteroid in combination with or without mycophenolate mofetil in living donor liver transplantation (LDLT) recipients infected with hepatitis B virus (HBV)., Methods: A randomized, open-label, comparative, multicenter, phase IV study was conducted with 119 patients from January 2014 to September 2017. In the full analysis set population, 58 and 59 patients were included in the study group (triple-drug regimen: TacroBell + My-rept + corticosteroid) and the control group (dual-drug regimen: TacroBell + corticosteroid), respectively. In the per protocol set population, 49 and 42 patients were included in the study and control groups, respectively., Results: In the full analysis set population, the incidence of biopsy-proven acute cellular rejection (rejection activity index score ≥4) was 3.4% in the study group; however, this finding was not observed in the control group (P = .468). Hepatitis B virus recurrence was observed in one patient in the control group. No cases of biopsy-proven acute cellular rejection and HBV recurrence were observed in the per protocol set population. The incidences of serious adverse events were 25.9% and 18.0% in the study and control groups, respectively; however, the difference between the groups was not statistically significant (P = .376)., Conclusion: Although the study involved a small number of patients, the triple-drug regimen can be considered safe and effective for immunosuppression after living donor liver transplantation in patients infected with HBV., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Adhesion G-protein-coupled receptors (aGPCRs) bear notable similarity to Notch proteins 1 , a class of surface receptors poised for mechano-proteolytic activation 2-4 , including an evolutionarily conserved mechanism of cleavage 5-8 . However, so far there is no unifying explanation for why aGPCRs are autoproteolytically processed. Here we introduce a genetically encoded sensor system to detect the dissociation events of aGPCR heterodimers into their constituent N-terminal and C-terminal fragments (NTFs and CTFs, respectively). An NTF release sensor (NRS) of the neural latrophilin-type aGPCR Cirl (ADGRL) 9-11 , from Drosophila melanogaster, is stimulated by mechanical force. Cirl-NRS activation indicates that receptor dissociation occurs in neurons and cortex glial cells. The release of NTFs from cortex glial cells requires trans-interaction between Cirl and its ligand, the Toll-like receptor Tollo (Toll-8) 12 , on neural progenitor cells, whereas expressing Cirl and Tollo in cis suppresses dissociation of the aGPCR. This interaction is necessary to control the size of the neuroblast pool in the central nervous system. We conclude that receptor autoproteolysis enables non-cell-autonomous activities of aGPCRs, and that the dissociation of aGPCRs is controlled by their ligand expression profile and by mechanical force. The NRS system will be helpful in elucidating the physiological roles and signal modulators of aGPCRs, which constitute a large untapped reservoir of drug targets for cardiovascular, immune, neuropsychiatric and neoplastic diseases 13 ., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

The rotational dynamics of fluorescent probes of different sizes in glass-forming materials were examined to correlate the time distribution and length scale of the dynamic heterogeneity (ξ het ). As the size of the probe increased, the temperature dependence of the rotation correlation time (τ c ) shifted to longer times, and from this shift, the length scale associated with the glass transition (ξ α ) was estimated through the Debye-Stokes-Einstein (DSE) relationship and the length scale of the probe (ξ sDFT ) estimated from quantum mechanical calculations. The estimated ξ α values roughly matched with ξ het obtained from calorimetric analysis but were considerably smaller than those deduced from 4D NMR, boson peak, and four-point dynamic susceptibility measurements but with a similar trend of decrease in the length scale upon the increase in the stretching exponent (β) of the system. Because β of the glass formers represents the time distribution of the system, and τ c is related to the weighted average of the distribution, the length-scale distribution of the glass transition can be deduced by adopting the DSE relationship and assuming ξ α is the weighted average of this distribution at the glass transition temperature. In such a case, the upper bound of the length scale and trend matches the experimentally obtained ξ het from 4D NMR, boson peak, and four-point dynamic susceptibility measurements. Furthermore, at a given temperature, as the probe size increased, the β value reported by the probe increased, whereas the temperature dependence of β, which strongly correlates with the fragility of the system, was independent of the probe size.

Objective: Anti-melanoma differentiation-associated protein 5 (MDA5)-positive DM is associated with rapidly progressive interstitial lung disease (RP-ILD) and high mortality. This multicentre retrospective study aimed to identify predictors of mortality and RP-ILD., Methods: Anti-MDA5-positive DM patients were identified from the Hong Kong Myositis Registry and the Clinical Data Analysis and Reporting System. Clinical characteristics were reviewed. Risk factors for mortality and RP-ILD were identified., Results: Among the 116 recruited patients, 100 (86.2%) had ILD, 47 (40.5%) had RP-ILD and 44 (37.9%) patients died. Cox regression analysis revealed RP-ILD [hazard ratio (HR) 9.735 (95% CI 3.905, 24.272)], age &gt;52 years [HR 4.750 (95% CI 1.692, 13.333)], ferritin level &gt;2800 pmol/l [HR 3.042 (95% CI 1.323, 6.997)] and lactate dehydrogenase (LDH) &gt;400 IU/l [HR 2.290 (95% CI 1.009, 5.198)] were independent predictors of mortality. With regard to RP-ILD, analyses showed that potential predictors at baseline included age &gt;50 years [HR 2.640 (95% CI 1.277, 5.455)], LDH &gt;300 IU/l [HR 3.189 (95% CI 1.469, 6.918)], fever [HR 1.903 (95% CI 0.956, 3.790)] and neutrophil:lymphocyte ratio &gt;7.0 [HR 1.967 (95% CI 0.942, 4.107)]. We proposed a prediction model based on fever, LDH, age and white cell count (FLAW) to stratify the risk of development of RP-ILD. The probability of RP-ILD in a patient with a score of 4 was 100%. A small internal validation cohort showed the odds of RP-ILD with FLAW scores of 0, 1, 2 and 3 were 0%, 0%, 42.9% and 75%, respectively., Conclusions: Anti-MDA5-associated RP-ILD is significantly associated with poor survival rates. The FLAW model maybe useful to predict the development of RP-ILD., (© The Author(s) 2022. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objective: To compare physician-level versus practice-level primary care continuity and their association with expenditure and acute care utilization among Medicare beneficiaries and evaluate whether continuity of outpatient primary care at either/both physician or/and practice level could be useful quality measures., Data Source: Medicare Fee-For-Service claims data for community dwelling beneficiaries without end-stage renal disease who were attributed to a national random sample of primary care practices billing Medicare (2011-2017)., Study Design: Retrospective secondary data analysis at per Medicare beneficiary per year level. We used multivariable linear regression with practice-level fixed effects to estimate continuity of care score at physician versus practice level and their associations with outcomes., Data Collection/extraction Method: We calculated clinician- and practice-level Bice-Boxerman continuity of care index scores, ranging from 0 to 1, using primary care outpatient claims. Medicare expenditures, hospital admissions, emergency department (ED) visits, and readmissions were obtained from the Medicare Beneficiary Summary File: Cost and Utilization Segment. Ambulatory care sensitive conditions (ACSC) were defined using diagnosis codes on inpatient claims., Principal Findings: We studied 2,359,400 beneficiaries who sought care from 13,926 physicians. Every 0.1 increase in physician continuity score was associated with a $151 reduction in expenditure per beneficiary per year (p < 0.01), and every 0.1 increase in practice continuity score was associated with $282 decrease (p < 0.01) per beneficiary per year. Both physician- and practice-level continuity were associated with lower Medicare expenditures among small, medium, and large practices. Both physician- and practice-level continuity were associated with lower probabilities of hospitalization, ED visit, admissions for ACSC, and readmission., Conclusions: Primary care continuity of care could serve as a potent value-based care quality metric. Physician-level continuity is a unique value center that cannot be supplanted by practice-level continuity., (© 2022 Health Research and Educational Trust.)

The development of safe artificial sweeteners has attracted considerable interest in the food industry. Previous machine learning (ML) studies based on quantitative structure-activity relationships have provided some molecular principles for predicting sweetness, but these models can be improved via the chemical recognition of sweetness active factors. Our ML model, a soft-vote ensemble model that has a light gradient boosting machine and uses both layered fingerprints and alvaDesc molecular descriptor features, demonstrates state-of-the-art performance, with an AUROC score of 0.961. Based on an analysis of feature importance and dataset, we identified that the number of nitrogen atoms that serve as hydrogen bond donors in molecules can play an essential role in determining sweetness. These results potentially provide an advanced understanding of the relationship between molecular structure and sweetness, which can be used to design new sweeteners based on molecular structural dependence., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Abstract: The Medical Student Summer Clinical Externship is an 8-wk program hosted by the Association of Academic Physiatrists and offered to first year medical students. Various institutions sponsor participants and provide clinical exposure and mentorship opportunities to promote interest in the field. The program has had more than 100 medical student participants. Students were asked to complete a preparticipation and postparticipation survey. Results revealed a statistically significant increase in interest in physiatry and participants' scores for comfort and experience level in obtaining a history of present illness, general physical examination, and managing developmental, musculoskeletal, and neurologic disabilities. The Medical Student Summer Clinical Externship program provides an opportunity for mentorship and exposure to various subspecialties that likely reinforces student interest in those who are predisposed to physiatry. Students' increased comfort level in treating patients with developmental, musculoskeletal, and neurologic disabilities may lead to improvements in the quality of and access to care received by these populations. All participants gain an increased awareness of the scope of practice of physiatry that will hopefully lead to the increased integration of physical medicine and rehabilitation into the care plans and as a standard of care for patients who might greatly benefit., Competing Interests: Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Background: The aim of this study was to validate the 2019 European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) classification criteria for systemic lupus erythematosus (SLE) in antinuclear antibody (ANA)-positive Chinese patients., Methods: Medical records of all adult patients who attended the rheumatology out-patient clinics between May and September 2019 were reviewed. Patients with ever ANA positive (titre ⩾1:80) were included and evaluated for the fulfilment of the 2019 EULAR/ACR, 2012 Systemic Lupus International Collaborating Clinics (SLICC) and 1997 ACR criteria for SLE classification. The performance of these criteria in predicting a clinical diagnosis of SLE as judged by an independent panel of rheumatologists was studied and compared in different subgroups., Results: A total of 1533 patients (88.2% women; age at first clinic attendance 45.5 ± 15.6 years) were studied and 562 patients were judged to be clinical SLE. The sensitivity and specificity of the EULAR/ACR (⩾10 points), SLICC and ACR criteria for a clinical diagnosis of SLE was 96.1%, 97.9% and 86.1%; and 85.8%, 86.3% and 94.3%, respectively. Applying the attribution rule to the non-SLE controls, the specificity of the three criteria increased to 95.0%, 92.5% and 98.8%, respectively. The specificity of the EULAR/ACR criteria was higher in male patients (97.9%), those aged >50 years (97.0%) and disease duration of ⩽3 years (97.6%). Using a cut-off of 12 points, the specificity of the EULAR/ACR criteria was further increased (96.6%) while a high sensitivity (95.0%) was maintained., Conclusion: In Chinese patients with a positive ANA, the EULAR/ACR criteria for clinical SLE perform equally well to the SLICC criteria. Both the EULAR/ACR and SLICC are more sensitive but less specific than the ACR criteria. The specificity of all the three criteria is enhanced by applying the attribution rule to controls. The specificity of the EULAR/ACR criteria is higher in certain patient subgroups or when the cut-off score is raised., Competing Interests: Conflict of interest statement: The authors declared no potential conflicts of interest with respect to the research, authorship and/or publication of this article., (© The Author(s), 2022.)

This study used an artificial intelligence (AI)-based crystal inverse-design approach to investigate the new phase of two-dimensional (2D) pristine magnesium hydride (Mg x H y ) sheets and verify their availability as a hydrogen storage medium. A 2D binary phase diagram for the generated crystal images was constructed, which was used to identify significant 2D crystal structures. Then, the electronic and dynamic properties of the Mg x H y sheets in low-energy periodic phases were identified via density functional theory (DFT) calculations; this revealed a previously unknown phase of 2D MgH 2 with a P 4̄ m 2 space group. In the proposed structure, the adsorption behaviors of the Li-decorated system were investigated for multiple hydrogen molecules. It was confirmed that Li-decorated MgH 2 has an expected theoretical gravimetric density of 6 wt%, with an average H 2 adsorption energy of -0.105 eV. Therefore, it is anticipated that P 4̄ m 2 MgH 2 sheets can be employed effectively as a medium for hydrogen storage. Additionally, this finding indicates that a deep learning-based approach is beneficial for exploring unrevealed 2D materials., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Objective: Severe maternal morbidity represents a "near miss" mortality and is an important measure of quality and safety. Racial inequity in maternal morbidity is stark and the reasons for this disparity are poorly understood. We aimed to identify states achieving racial equity in maternal morbidity in order to identify policies that may promote racial equity., Methods: We analyzed Medicaid deliveries from 2008 to 2009 in a sample that included 28 states and the District of Columbia. This dataset included approximately 80% of all Medicaid enrollees and 90% of minority Medicaid enrollees in the US. We determined the Non-Hispanic Black/Non-Hispanic white SMMI rate ratio for each state and categorized the states into groups by rate ratio. We described demographic features of both the general population and study population for these groups of states., Results: In a sample that included a total of 1,489,134 births, we found that no state/district is achieving equity in severe maternal morbidity. The severe maternal morbidity rate is higher for Non-Hispanic Black than Non-Hispanic white patients in every state included. With a rate ratio ranging from 1.14 to 2.66, there are varying degrees of inequity. States in the group with the most equitable maternal morbidity rates had less inequity across racial subgroups with respect to educational attainment and poverty., Conclusions: Identifying geographic areas with varying degrees of inequity may be key to identifying policies to promote equity. Socioecological disparities and inadequate access to care may be factors in racial inequity in maternal morbidity., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: 18F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) is a useful tool for identifying high-risk features in patients with newly diagnosed multiple myeloma (NDMM). This study evaluated the role of autologous stem cell transplantation (ASCT) in patients presenting with positive results on PET/CT scans., Materials and Methods: The medical records of 210 patients who underwent PET/CT at diagnosis were retrospectively reviewed. Eligible patients for transplantation proceeded to upfront ASCT with high-dose chemotherapy (HDT) after induction therapy with novel agents., Results: The presence of a number of focal lesions (FL) >3 and extramedullary disease (EMD) occurred in 111 and 35 patients, respectively. ASCT was performed in 54 patients. Among patients with FL > 3, those treated with ASCT showed a prolonged 2-year progression-free survival (PFS) and overall survival (OS) rates compared to those not treated with ASCT (PFS, 60.2% vs. 23.5%, P < 0.001; OS, 91.7% vs. 63.6%, P = 0.005). In patients with FL ≤ 3, treatment by ASCT was associated with a higher 2-year PFS rate than no treatment by ASCT (74.0% vs. 54.9%, P = 0.040). The OS of patients treated with ASCT was not significantly longer than that of patients not treated with ASCT (P = 0.115). In multivariate analysis, FL > 3, Revised International Staging System (R-ISS), and upfront ASCT were independent prognostic factors for PFS and OS., Conclusion: Presenting FL > 3 on baseline PET/CT represents a high-risk feature in patients with NDMM. Frontline ASCT with HDT prolonged the survival of patients with FL > 3., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Vanadium selenide (V 2 Se 9 ) is a true one-dimensional (1D) crystal composed of atomic nanochains bonded by van der Waals (vdW) interactions. Recent experiments revealed the mechanical exfoliation of newly synthesized V 2 Se 9 . In this study, we predicted the electronic and transport properties of V 2 Se 9 through computational analyses. We calculated the intrinsic carrier mobility of V 2 Se 9 monolayers (MLs) and nanoribbons (NRs) using density functional theory and deformation potential theory. We found that the electron mobility of the two-dimensional (2D) (010)-plane ML of V 2 Se 9 is highly anisotropic, reachingμ2D,ze=1327cm 2 V -1 s -1 across the chain direction. The electron mobility of 1D NR systems in a (010)-plane ML of V 2 Se 9 along the chain direction continuously increased as the thickness increased from 1-chain to 4-chain NR (width below 3 nm). Interestingly, the electron mobility of 1D 4-chain NR along the chain direction (μ1D,xe=775cm 2 V -1 s -1 ) was higher than that of a 2D (010)-plane ML (μ2D,xe=567cm 2 V -1 s -1 ). These results demonstrate the potential of vdW-1D crystal V 2 Se 9 as a new nanomaterial for ultranarrow (sub-3 nm width) optoelectronic devices with high electron mobility., (© 2022 IOP Publishing Ltd.)

Background: While primary care clinicians are being trained to use buprenorphine for the treatment of Opioid Use Disorder (OUD) in order to increase access to addiction treatment, it is not known what impact such training and subsequent experience treating patients with OUD has on full agonist opioid prescribing., Methods: This retrospective cohort study compares the full agonist opioid prescribing patterns of Drug Addiction Treatment Act (DATA)-waivered ("X-waivered") primary care clinicians to non-trained, non-waivered clinicians in a rural health network. X-waivered clinicians also received Project ECHO training and telementoring support for one year. Using prescriber data generated by an electronic medical record system, opioid prescribing and morphine milligram equivalents (MME) per day per patient were calculated. A between-group analysis was used to compare the study groups six months pre-versus post-training., Results: Although the mean number of full agonist opioid prescriptions per clinician and per 100 patient encounters decreased among all clinicians, there was no change in full agonist opioid prescribing MME. As expected, buprenorphine prescribing by X-waivered, trained clinicians increased significantly post-training., Conclusions : X-waivers plus Project ECHO support for the treatment of OUD using buprenorphine had no effect on full agonist opioid prescribing by primary care clinicians.

Recently, ternary transition metal chalcogenides Ta 2 X 3 Se 8 (X = Pd or Pt) have attracted great interest as a class of emerging one-dimensional (1D) van der Waals (vdW) materials. In particular, Ta 2 Pd 3 Se 8 has been actively studied owing to its excellent charge transport properties as an n-type semiconductor and ultralong ballistic phonon transport properties. Compared to subsequent studies on the Pd-containing material, Ta 2 Pt 3 Se 8 , another member of this class of materials has been considerably less explored despite its promising electrical properties as a p-type semiconductor. Herein, we demonstrate the electrical properties of Ta 2 Pt 3 Se 8 as a promising channel material for nanoelectronic applications. High-quality bulk Ta 2 Pt 3 Se 8 single crystals were successfully synthesized by a one-step vapor transport reaction. Scanning Kelvin probe microscopy measurements were used to investigate the surface potential difference and work function of the Ta 2 Pt 3 Se 8 nanoribbons of various thicknesses. Field-effect transistors fabricated on exfoliated Ta 2 Pt 3 Se 8 nanoribbons exhibited moderate p-type transport properties with a maximum hole mobility of 5 cm 2 V -1 s -1 and an I on / I off ratio of >10 4 . Furthermore, the charge transport mechanism of Ta 2 Pt 3 Se 8 was analyzed by temperature-dependent transport measurements in the temperature range from 90 to 320 K. To include Ta 2 Pt 3 Se 8 in a building block for modern 1D electronics, we demonstrate p-n junction characteristics using the electron beam doping method.

Finding new materials with satisfying all the desired criteria for nanodevices is an extremely difficult work. Here, we introduce a novel Nb 2 Se 9 material as a promising candidate, capable of overcoming some physical limitations, such as a suitable band gap, high carrier mobility, and chemical stability. Unlike graphene, it has a noticeable band gap and no dangling bonds at surfaces that deteriorate transport properties, owing to its molecular chain structure. Using density functional theory (DFT) calculations with deformation potential (DP) theory, we find that the electron mobility of 2D Nb 2 Se 9 across the axis direction reaches up to 2.56 × 10 3 cm 2 V -1 s -1 and is approximately 2.5-6 times higher than the mobility of other 2D materials, such as MoS 2 , black phosphorous, and InSe, at room temperature. Moreover, the mobility of 2D Nb 2 Se 9 is highly anisotropic (μ a /μ c ≈ 6.5). We demonstrate the potential of 2D Nb 2 Se 9 for applications in nanoscale electronic devices and, possibly, mid-infrared photodetectors., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

In this study, high-purity and centimeter-scale bulk Ta 2 Ni 3 Se 8 crystals are obtained by controlling the growth temperature and stoichiometric ratio between tantalum, nickel, and selenium. It is demonstrated that the bulk Ta 2 Ni 3 Se 8 crystals could be effectively exfoliated into a few chain-scale nanowires through simple mechanical exfoliation and liquid-phase exfoliation. Also, the calculation of electronic band structures confirms that Ta 2 Ni 3 Se 8 is a semiconducting material with a small bandgap. A field-effect transistor is successfully fabricated on the mechanically exfoliated Ta 2 Ni 3 Se 8 nanowires. Transport measurements at room temperature reveal that Ta 2 Ni 3 Se 8 nanowires exhibit ambipolar semiconducting behavior with maximum mobilities of 20.3 and 3.52 cm 2 V -1 s -1 for electrons and holes, respectively. The temperature-dependent transport measurement (from 90 to 295 K) confirms the carrier transport mechanism of Ta 2 Ni 3 Se 8 nanowires. Based on these characteristics, the obtained 1D vdW material is expected to be a potential candidate for additional 1D materials as channel materials., (© 2021 Wiley-VCH GmbH.)

Purpose: When splitting a liver for adult and pediatric graft recipients, the retained left medial section (S4) will undergo ischemic necrosis and the right trisection graft becomes an extended right liver (ERL) graft. We investigated the fates of the retained S4 and its prognostic impact in adult split liver transplantation (SLT) using an ERL graft., Methods: This was a retrospective analysis of 25 adult SLT recipients who received split ERL grafts., Results: The mean model for end-stage liver disease (MELD) score was 27.3 ± 10.9 and graft-recipient weight ratio (GRWR) was 1.98 ± 0.44. The mean donor age was 26.5 ± 7.7 years. The split ERL graft weight was 1,181.5 ± 252.8 g, which resulted in a mean GRWR of 1.98 ± 0.44. Computed tomography of the retained S4 parenchyma revealed small ischemic necrosis in 16 patients (64.0%) and large ischemic necrosis in the remaining 9 patients (36.0%). No S4-associated biliary complications were developed. The mean GRWR was 1.87 ± 0.43 in the 9 patients with large ischemic necrosis and 2.10 ± 0.44 in the 15 cases with small ischemic necrosis (P = 0.283). The retained S4 parenchyma showed gradual atrophy on follow-up imaging studies. The amount of S4 ischemic necrosis was not associated with graft (P = 0.592) or patient (P = 0.243) survival. A MELD score of >30 and pretransplant ventilator support were associated with inferior outcomes., Conclusion: The amount of S4 ischemic necrosis is not a prognostic factor in adult SLT recipients, probably due to a sufficiently large GRWR., Competing Interests: Conflict of Interest: No potential conflict of interest relevant to this article was reported., (Copyright © 2021, the Korean Surgical Society.)

Objective: To investigate the association between the aryl hydrocarbon receptor repressor (AhRR) C/G polymorphisms and glutathione-S-transferase M1 (GSTM1) and GSTT1 null mutation and the risk of polycystic ovary syndrome (PCOS) in Korean women., Methods: This was a case-control study of 478 women with PCOS and 376 aged-matched healthy controls. Genotyping of the AhRR C/G polymorphism and GSTM1 and GSTT1 were performed using real-time PCR analysis and multiplex PCR, respectively., Results: The genotype distribution of the AhRR C/G polymorphisms and GSTM1/GSTT1 null mutations did not differ between women with PCOS and controls. Using the wild-type combined AhRR CC and GSTT1 present genotype as a reference, the odds that a woman had PCOS were 1.54 (95% CIs 1.04-2.29) times higher if she had a combined AhRR CG or GG and GSTT1 null genotype. The odds that a woman had PCOS was 1.48 (95% CIs 1.08-2.04) times higher if she had a combined GSTM1/GSTT1 null genotype compared with the wild-type combined GSTM1/GSTT1 present genotype. However, there were no significant associations between the risk of PCOS and any combined AhRR and GSTM1., Conclusions: Our data suggest that a combined AhRR CG or GG and GSTT1 null genotype or a combined GSTT1/GSTM1 null genotype might be associated with an increased risk of PCOS.

Background: Wide surgical excision is the gold standard for basal cell carcinoma (BCC) treatment. Typically, resection requires a safety margin ≥ 4 mm. We aimed to confirm BCC excisions' cancer recurrence rate and safety on the facial region with new safety margins., Methods: We included patients with primary BCC on the facial region who underwent wide excision with 2- or 3-mm safety margins at our institution between January 2010 and December 2018. Medical records were reviewed to confirm the epidemiology and surgical information. Recurrence was confirmed by physical examination through regular 6-month follow-up., Results: We included 184 out of 233 patients in this study after applying the exclusion criteria. The mean age and follow-up period were 71.2± 10.2 years and 29.3± 13.5 months, respectively. The predominantly affected area was the nose (95 cases); a V-Y advancement flap was the most commonly used surgical method. There were two cases of recurrence in the 2 mm margin group and one recurrence in the group resected with 3 mm margins., Conclusion: In this large cohort study, we found 2-3 mm excision margins can yield enough safety in facial BCCs. The recurrence rates were found to be comparable with those reported after wider margins.

At the end of 2019, the cause of pneumonia outbreaks in Wuhan, China, was identified as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In February 2020, the World Health Organization named the disease cause by SARS-CoV-2 as coronavirus disease 2019 (COVID-19). In response to the pandemic, the Korean Cancer Association formed the COVID-19 task force to develop practice guidelines. This special article introduces the clinical practice guidelines for cancer patients which will help oncologists best manage cancer patients during the COVID-19 pandemic.

G protein-coupled receptors (GPCRs) represent a major group of drug targets with tremendous pharmacological value. Signals arising from GPCRs are primarily transduced via two functional components of their corresponding G proteins, the Gα subunit and the Gβγ dimer that dissociate from each other upon activation of the heterotrimer (Gαβγ). The Gβγ dimer has become an increasingly popular subject in GPCR signaling, owing to its numerous effectors and notable roles in signal integration. Because Gβγ dimers participate in a wide range of intracellular processes that regulate cellular physiology, they are often implicated in the pathology of various diseases. Yet, one caveat to the current 'Dissociation Model' on GPCR signaling is that unequivocal Gβγ signals are biasedly detected with G i/o -coupled receptors, while Gβγ signals from G s - or G q -coupled receptors seem to play an auxiliary role. In this review, we revisit the evidence for or against the 'Dissociation Model' and discuss in detail several hypotheses that may explain such disparity and provide alternative interpretations to accommodate the 'biased Gβγ signals' observed in different biological systems. The issue of whether unique combinations of Gβγ dimer can confer signaling specificity is also discussed in the context of physiological relevance., (© 2020 Federation of European Biochemical Societies.)

Aim: The aim of the study was to estimate the prevalence of pelvic insufficiency fractures (PIFs) after radiation therapy (RT) in patients with cervical cancer., Patients and Methods: A total of 3,633 patients from 15 cohort studies were included. Proportion meta-analysis was performed to estimate prevalence and subgroup analysis was performed according to imaging modalities for diagnosis of PIF. For continuous variables (age and length of follow-up), meta-regression analysis was performed., Results: Pooled prevalence estimate of PIF was 14% (95% CI=10-19). Incidence of PIF was higher in studies that used MRI as a diagnostic tool (17%, 95% CI=12-22) than non-MRI (8%, 95% CI=2-14). In meta-regression, we found a significant association of prevalence of PIF with age (p=0.021) but not with length of follow-up (p=0.118)., Conclusion: PIF after RT in patients with cervical cancer is not rare. Physicians need to pay attention to PIFs, especially in patients with high-risk factors for osteoporotic fracture., (Copyright© 2021, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

We discovered the efficient catalyst-free, photo-mediated oxidative cyclization reaction of bis- p -pyridinium benzoyl hydrazone (BH1) to 2-pyridinium-5-phenyl-1,3,4-oxadiazoles. This photoreaction is remarkable because it does not require additives ( e.g. , bases, strong oxidants, or photocatalysts), which are essential in previous reports, and proceeds very effectively even with solid-state microporous organic polymers. Interestingly, we found that the inclusion complexation of BH1 with cucurbit[7]uril (CB7) interferes with the photo-induced electron transfer from BH1 to molecular oxygen through modification of the LUMO energy level, thus inhibiting the photo-medicated oxidative cyclization., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Background: More than 400 liver transplants were performed at Asan Medical Center (AMC) in 2011, and over 500 liver transplants including 420 living-donor liver transplants (LDLTs) were performed in 2019. Herein, we report the methodology of these procedures., Methods: Since the first adult LDLTs at AMC using the left and right lobes were successfully performed, various innovative techniques and approaches have been developed: modified right lobe, dual graft, donor exchange for ABO incompatibility, expansion of indications and no-touch techniques for hepatocellular carcinoma, intraoperative cine-portogram and additional intervention for large collaterals, management of portal vein thrombosis (PVT) and stenosis, salvage LDLT after major hepatectomy, and timely LDLT for patients with acute-on-chronic liver failure., Results: Four hundred twenty LDLTs in 403 adult and 17 pediatric patients and 85 deceased-donor liver transplants in 74 adult and 11 pediatric patients were performed. The number of deceased-donor liver transplants remained constant since 2011, but the number of LDLTs increased steadily. One hundred thirty patients (25.7%) required urgent liver transplantations and 24 patients with acute-on-chronic liver failure underwent LDLT. PVT including grade 1,2,3, and 4 was reported in 91 patients (18.0%), and Yerdel's grade 2, 3, and 4 PVT was reported in 47 patients (51.6%); all patients with PVT were successfully treated. Adult LDLTs for hepatocellular carcinoma and ABO incompatibility accounted for 52.6% and 24.3% of the cases, respectively. In-hospital mortality in 2019 was 2.97%., Conclusion: Continual efforts to overcome challenging problems in LDLT with various innovations and dedication of the team members during the perioperative period to improve patient outcomes were crucial in increasing the number of liver transplantations at Asan Medical Center., (Copyright © 2020. Published by Elsevier Inc.)

True one-dimensional (1D) van der Waals materials can form two-dimensional (2D) dangling-bond-free anisotropic surfaces. Dangling bonds on surfaces act as defects for transporting charge carriers. In this study, we consider true 1D materials to be V 2 Se 9 chains, and then the electronic structures of 2D sheets composed of true 1D V 2 Se 9 chains are calculated. The (010) plane has indirect bandgap with 0.757 eV (1.768 eV), while the (111̅) plane shows a nearly direct bandgap of 1.047 eV (2.118 eV) for DFT-D3 (HSE06) correction, respectively. The (111̅) plane of V 2 Se 9 is expected to be used in optoelectronic devices because it contains a nearly direct bandgap. Partial charge analysis indicates that the (010) plane exhibits interchain interaction is stronger than the (111̅) plane. To investigate the strain effect, we increased the interchain distance of planes until an indirect-to-direct bandgap transition occurred. The (010) plane then demonstrated a direct bandgap when interchain distance increased by 30%, while the (111̅) plane demonstrated a direct bandgap when the interchain distance increased by 10%. In mechanical sensors, this change in the bandgap was induced by the interchain distance.