Metal-Insulator Transition and Emergent Gapped Phase in the Surface-Doped 2D Semiconductor 2H-MoTe_{2}

Artificially created two-dimensional (2D) interfaces or structures are ideal for seeking exotic phase transitions due to their highly tunable carrier density and interfacially enhanced many-body interactions. Here, we report the discovery of a metal-insulator transition (MIT) and an emergent gapped phase in the metal-semiconductor interface that is created in 2H-MoTe_{2} via alkali-metal deposition. Using angle-resolved photoemission spectroscopy, we found that the electron-phonon coupling is strong at the interface as characterized by a clear observation of replica shake-off bands. Such strong electron-phonon coupling interplays with disorder scattering, leading to an Anderson localization of polarons which could explain the MIT. The domelike emergent gapped phase could then be attributed to a polaron extended state or phonon-mediated superconductivity. Our results demonstrate the capability of alkali-metal deposition as an effective method to enhance the many-body interactions in 2D semiconductors. The surface-doped 2H-MoTe_{2} is a promising candidate for realizing polaronic insulator and high-T_{c} superconductivity.

[Analysis on death trend in AIDS patients and related risk factors in China]

Objective: To understand the basic characteristics of death cases, analyze the death trends in AIDS patients and the risk factors in China and provide evidence for the development of AIDS prevention and control strategy. Methods: The data were collected from the national basic information system of HIV/AIDS. The information of the cases in AIDS phase were used. The death number and mortality trends in AIDS cases were described, and Cox Proportion Hazards Regression Model was constructed to assess hazard ratios (HR) for independent variables. Results: By the end of 2019, a total of 582 472 AIDS cases, including 168 391 deaths, had been reported in China. Among the death cases, males accounted for 76.8% (129 343/168 391), heterosexual contact was the main transmission route, accounting for 60.9% (102 516/168 391). The proportion of the death cases who had ever received ART was 54.0% (90 888/168 391). The inter-quartile (P₂₅, P₇₅) of first CD₄^＋T cells counts (CD₄) was 34 cells/μl, 240 cells/μl. Up to 43.5% (73 191/168 391) of the deaths occurred within one year after diagnosis. From 2007 to 2019, the annual death number increased from 5 485 to 18 737, the mortality rates decreased form 10.9%% to 4.3%. The average time interval from diagnosis to death ranged from 1.4 year to 4.0 years, showing increase trend by year. The results of Cox regression analysis showed that older age (50- years old: HR=1.50; ≥65 years old: HR=2.00), being male (HR=1.44)、being in minority ethnic group (HR=1.10), having lower first CD₄ levels (0- cells/μl, HR=2.73;200- cells/μl, HR=1.33; 350- cells/μl,HR=1.13), heterosexual transmission route (HR=1.64) and injecting drug use (HR=1.79) were the risk factors related to deaths in AIDS patients. The higher educational levels (junior middle school: HR=0.86, senior high school and above: HR=0.59) and receiving antiviral treatrment (HR=0.09) were protective factors. Conclusions: The number of death cases increased, meanwhile the mortality rates decrease year by year in AIDS patients in China during 2007-2019. It is necessary to strengthen the early detection and treatment of AIDS to reduce the mortality.

[Estimation of newly HIV infection trend by using the back-calculation method in Honghe Hani and Yi autonomous prefecture]

Objective: Using the changing patterns of CD(4)(+) lymphocytes (CD(4)) counts of HIV/AIDS cases, we tried to estimate the number of newly infected HIV in Honghe Hani and Yi autonomous prefecture (Honghe prefecture) Yunnan province, and to provide reference for evaluating the trend of local HIV epidemic. Methods: Among diagnosed HIV infections, those who were at ≥15 years old, having available initial CD(4) records of testing, initiating antiviral therapy before the end of 2018, were selected from the case reporting system of Honghe prefecture, Yunnan province. Both Depletion model of the square root on CD(4) and the time of infection were used to back-calculate the seroconversion time of each individual. Both direct probability distribution method and life table method were used to calculate the distribution rates of diagnosis and the weight of delay. The number of diagnoses over the years was used to reversely estimate the total number of newly HIV infections. Results: At the end of 2018, the total number of HIV infections was estimated 35 977 with the rate of diagnosis as 77.50% in Honghe prefecture of Yunnan province. The number of new HIV infections appeared as 23 792 in 2008-2018. Cumulatively, the number of new HIV infections was 12 185 up to 2007. The estimated number of new HIV infections decreased from 2 602 in 2008 to 1 480 in 2018. The weight of diagnostic delay decreased from 5.49 in one year to 1.00 in 20 years, and the diagnosis rate increased from 18.2% to 100.0% during 20 years. Conclusion: In Honghe prefecture of Yunnan province, the number of newly infection showed a declining trend but the diagnostic rate was still far from reaching the "first 90% target" . It is expected to expand the timeliness on detection and case-finding so as to reduce the risk of HIV transmission.

[Characteristics and trends of newly reported HIV infection in young students in China, 2010-2019]

Objective: To analyze the characteristics and trends of newly reported HIV infection cases in young students in China between 2010 and 2019 and provide evidence for the formulation of AIDS prevention and control measures in young students. Methods: Data were collected from the Basic Web-based HIV/AIDS Case Reporting System. The HIV infection cases in students aged 15-24 years reported between 2010 and 2019 were selected. Their basic characteristics were described, and Joinpoint Regression Model was used to analyze the temporal trends of new diagnosis rates in different age groups. Results: A total of 23 307 HIV/AIDS cases were reported in young students, the male to female ratio was 33.9∶1 (22 640∶667), and the mean age was (19.9±2.05) years. The temporal trends of new diagnosis rates showed two stages, it increased rapidly between 2010 and 2015 (annual percentage changes, APC=32.1), and kept stable between 2015 and 2019 (APC=0.1, P>0.05). The new diagnosis rates in all age groups showed increasing trends between 2010 and 2015, and the APC of age group 15-17 years was highest (30.2). Between 2015 and 2019, the new diagnosis rates in age group 23-24 years showed decreasing trend (APC=-17.0). The transmission route was mainly homosexual contact for males, and heterosexual contact for females. For most heterosexual transmission cases, they were infected through non-marital or non-commercial heterosexual contact. The male cases mainly came from HIV voluntary counseling and testing clinics, but the female cases were mainly found in hospitals. The male cases had higher mean first CD(4)(+)T cells counts (CD(4)) compared with female cases (t=3.917, P=0.000). Conclusions: The overall increase trend of newly reported HIV infection in young students slowed slow down trend between 2010 and 2019, but the newly reported HIV infections in age group 15-17 years still showed an increase trend. It is necessary to carry out sex health education effectively in young students to reduce the high-risk sexual behavior and expand HIV test coverage in students.

Band insulator to Mott insulator transition in 1T-TaS2

1T-TaS₂ undergoes successive phase transitions upon cooling and eventually enters an insulating state of mysterious origin. Some consider this state to be a band insulator with interlayer stacking order, yet others attribute it to Mott physics that support a quantum spin liquid state. Here, we determine the electronic and structural properties of 1T-TaS₂ using angle-resolved photoemission spectroscopy and X-Ray diffraction. At low temperatures, the 2π/2c-periodic band dispersion, along with half-integer-indexed diffraction peaks along the c axis, unambiguously indicates that the ground state of 1T-TaS₂ is a band insulator with interlayer dimerization. Upon heating, however, the system undergoes a transition into a Mott insulating state, which only exists in a narrow temperature window. Our results refute the idea of searching for quantum magnetism in 1T-TaS₂ only at low temperatures, and highlight the competition between on-site Coulomb repulsion and interlayer hopping as a crucial aspect for understanding the material’s electronic properties.

1T-TaS2 possesses complex electronic phase behaviors in transition-metal di-chalcogenides, undergoing several charge-ordered phases before finally into an insulating state of unknown origin. Here, the authors determine its electronic and structural properties experimentally, revealing its origin.

Isostructural Spin-Density-Wave and Superconducting Gap Anisotropies in Iron-Arsenide Superconductors

When passing through a phase transition, electronic system saves energy by opening energy gaps at the Fermi level. Delineating the energy gap anisotropy provides insights into the origin of the interactions that drive the phase transition. Here, we report the angle-resolved photoemission spectroscopy (ARPES) study on the detailed gap anisotropies in both the tetragonal magnetic and superconducting phases in Sr_{1-x}Na_{x}Fe_{2}As_{2}. First, we found that the spin-density-wave (SDW) gap is strongly anisotropic in the tetragonal magnetic phase. The gap magnitude correlates with the orbital character of Fermi surface closely. Second, we found that the SDW gap anisotropy is isostructural to the superconducting gap anisotropy regarding to the angular dependence, gap minima locations, and relative gap magnitudes. Our results indicate that the superconducting pairing interaction and magnetic interaction share the same origin. The intraorbital scattering plays an important role in constructing these interactions resulting in the orbital-selective magnetism and superconductivity in iron-based superconductors.

Effects of assist parameter on the performance of proportional assist ventilation in a lung model of chronic obstructive pulmonary disease

BACKGROUND

How the assist parameters affect synchronization and inspiratory workload in proportional assist ventilation (PAV) remains unknown.

PURPOSE

This bench study aimed to optimize the PAV parameters by evaluating their effects on patient-ventilator synchrony and work of breathing (WOB) in a chronic obstructive pulmonary disease (COPD) model during noninvasive ventilation, compared with the pressure support ventilation (PSV) mode.

METHODS

The Respironics V60 ventilator was connected to an ASL5000 lung simulator, which simulates lung mechanics in COPD (compliance, 50mL/cmH₂O; expiratory resistance, 20 cmH₂O/L/s; respiratory rate, 15 breaths/min; inspiratory time, 1.6 s). PAV was applied with different assistance levels, including flow assist (FA, 40-90% respiratory resistance) and volume assist (VA, 50-90% elastance). PSV was assessed using the same model. Measurements were obtained at a leak flow rate of 25-28 L/min. Performance characteristics, simulator-ventilator synchrony, and WOB were assessed.

RESULTS

Runaway was prone to occur, and severe premature cycling was observed with VA75+FA level>65%. Compared with PSV, lower tidal volume (≤400mL) was observed during PAV with VA75+FA40-50 and FA50+VA40-80; similar and improved cycling synchrony was observed for FA50+VA80 and FA50+VA90 (cycling delay: -117.60±6.13 and -61.50±8.03 vs. -101.20±7.32ms). The reduced triggering workload was observed for VA75+FA60-65 and FA50+VA80-90. Total and patient WOB was improved with all tested assist level combinations, except for FA50+VA90.

CONCLUSIONS

PAV reduces WOB but can induce asynchrony if improper settings are set, but the most optimal settings still need more clinical observations.

[Analysis of reasons for failure of Meek micro-skin grafting in children with severe burn and treatment measures]

Objective: To analyze the reasons for failure of Meek micro-skin grafting in children with severe burns and to observe the clinical effects of the treatment measures. Methods: Thirty children with severe burns hospitalized in the First Affiliated Hospital of Anhui Medical University (hereinafter referred to as the author's affiliation) from January 2012 to January 2018, conforming to the inclusion criteria were included to failed skin graft group. Children in failed skin graft group were performed with Meek micro-skin grafting operation and the operation failed, including 17 males and 13 females aged 1 to 12 year(s). Thirty children with severe burns hospitalized in the author's affiliation during the same period of time, conforming to the inclusion criteria, were included to successful skin graft group. Children in successful skin graft group were performed with Meek micro-skin grafting operation and the operation succeeded, including 16 males and 14 females aged 1 to 12 year(s). Main treatment measures and effects before operation, area and survival rate of Meek micro-skin graft, infected pathogens status, selection status of sensitive antibiotics, preoperative nutrition status, and wound infection status in plum rain season of children in the two groups, and nutritional status before and after strengthening nutritional support of postoperative surviving children in failed skin graft group were analyzed retrospectively. Data were processed with chi-square test and t test. Results: (1) The numbers of children in the two groups performed with main treatment measures of dilatation and anti-shock, tracheotomy intubation, ventilator-assisted respiration, and limb incision decompression after admission were close (χ(2)=0, 0.016, 0.025, 0.009, P>0.05). After taking the above-mentioned main treatment measures, effects of correcting shock, preventing asphyxia, correcting breathing difficulty, and improving peripheral circulation of limb were achieved. (2) The area of Meek micro-skin grafting of children in successful skin graft group was (20.6±2.5)% total body surface area (TBSA), close to (21.2±2.2)% TBSA in failed skin graft group (t=0.534, P>0.05). The survival rate of Meek micro-skin graft of children in successful skin graft group was (79±5)%, significantly higher than (26±3)% in failed skin graft group (t=2.956, P<0.01). (3) The microbial culture of wound secretion of 5 (16.67%) children in 30 patients in successful skin graft group was positive, with Pseudomonas aeruginosa of 2 children, and Escherichia coli, Staphylococcus aureus, and Aspergillus of one patient respectively. As children in successful skin graft group were with no symptom of systemic infection, no blood microbial culture was done. The microbial culture of wound secretion of 30 (100.00%) children in 30 patients in failed skin graft group was positive, and blood microbial culture of 8 (26.67%) children was positive. The main pathogen was Pseudomonas aeruginosa of 11 (36.67%) children in 8 pathogens caused infection with gram-negative bacteria of 22 (73.33%), gram-positive bacteria of 11 (36.67%) children, and fungi of 6 (20.00%) children. (4) Ten kinds of sensitive antibiotics such as cephalosporins, glycopeptides, carbapenems, and tetracyclines antibiotics were used in children in failed skin graft group, of which the use rate of imipenem of 9 (30.00%) was the highest. Only 4 kinds of sensitive antibiotics such as ceftazidime were used in 30 children in successful skin graft group. (5) The preoperative levels of albumin and prealbumin of children in successful skin graft group were (32±4) g/L and (133±41) mg/L respectively, significantly higher than (27±4) g/L and (93±35) mg/L in failed skin graft group (t=5.090, 4.064, P<0.01). The albumin and prealbumin levels of postoperative surviving children in failed skin graft group after nutritional support treatment were (35±4) g/L and (168±49) mg/L, significantly higher than (27±4) g/L and (94±38) mg/L before nutritional support treatment (t=6.911, 6.315, P<0.01). (6) Wound infection of 9 children in 30 children with wound infection in failed skin graft group happened in the plum rain season, and fungi infection of 3 children in 6 children with fungi infection happened in the plum rain season. Wound infection of 2 children in 5 children with wound infection in successful skin graft group happened in the plum rain season, and the only one children with fungi infection happened in the plum rain season. Conclusions: The main reasons for the failure of Meek micro-skin grafting in children with severe burns include infection, nutrition, and season factors, etc. Measures of strengthening wound dressing change, reasonable use of sensitive antibiotics to control infection, internal and external intestinal nutritional support, and reducing disturbance of the plum rain season by enhancing ventilation are effective and worthy of clinical promotion.

Association between phosphodiesterase type 5 inhibitors use and risk of melanoma: a meta-analysis

This meta-analysis aimed to clarify the actual association between the phosphodiesterase type 5 inhibitors (PDE5-Is) use and the risk of melanoma in erectile dysfunction (ED) patients. A systematic literature search was conducted in online databases in October, 2016 to identify studies focusing on the association between PDE5-Is use and the risk of melanoma. Summarized multivariate adjusted risk ratios (RRs) and 95% confidence intervals (CIs) were calculated to assess the strength of associations. A total of six clinical trials containing more than one million participants were included. ED patients  using PDE5-Is shared a significant high risk of melanoma (RR=1.12, 95% CI=1.03-1.21, p=0.006). Positive associations were observed in all kinds of prescriptions: single prescription (RR=1.20, 95% CI=1.06-1.35, p=0.003), medium number of prescription (RR=1.15, 95% CI=1.01-1.30, p=0.03), and high number of prescription (RR=1.18, 95% CI=1.05-1.34, P=0.006). Additionally, PDE5-Is were also found to be significantly associated with increased risk of basal cell carcinoma (RR=1.14, 95% CI=1.09-1.19, p<0.00001). Our study indicates that PDE5-Is use could significantly increase the risk of melanoma and basal cell carcinoma. However, the risk of melanoma did not rise significantly with the increased number of prescriptions. Consequently, owing to the lack of information about other potential synergistic factors, it is difficult for us to make a solid conclusion that application of PDE5-Is is the direct cause of increased risk of melanoma. Their relationship needs to be validated by further evidences.

Prevalence, distribution and risk factors of farmer reported swine influenza infection in Guangdong Province, China

A cross-sectional study was undertaken to better understand the husbandry, management and biosecurity practices of pig farms in Guangdong Province (GD), China to identify risk factors for farmer reported swine influenza (SI) on their farms. Questionnaires were administered to 153 owners/managers of piggeries (average of 7 from each of the 21 prefectures in GD). Univariable and multivariable logistic regression analyses were used to identify risk factors for farmer reported SI in piggeries during the six months preceding the questionnaire administration. The ability of wild birds to enter piggeries (OR 2.50, 95% CI: 1.01-6.16), the presence of poultry on a pig-farm (OR 3.24, 95% CI: 1.52-6.94) and no biosecurity measures applied to workers before entry to the piggery (OR 2.65, 95% CI: 1.04-6.78) were found to increase the likelihood of SI being reported by farmers in a multivariable logistic regression model. The findings of this study highlight the importance of understanding the local pig industry and the practices adopted when developing control measures to reduce the risk of SI to pig farms.

Clofazimine improves clinical outcomes in multidrug-resistant tuberculosis: a randomized controlled trial

OBJECTIVES

We carried out a randomized multicentre study in China to investigate whether the clofazimine would improve the efficacy of the standardized regimen in patients with multidrug-resistant tuberculosis (MDR-TB).

METHODS

Patients with MDR-TB managed in 17 TB specialist hospitals in China between September 2009 and September 2011 were randomly assigned to the treatment groups at enrolment. In the intervention group, 100 mg clofazimine per day was added to the standardized regimen. The primary outcome was the proportion of patients with successful outcomes.

RESULTS

From the 156 patients that were screened, 74 were assigned to the control group and 66 to the clofazimine group. Of the 66 cases analysed for clinical outcome in the clofazimine group, 36 patients were cured, and seven completed treatment, yielding a favourable outcome rate of 65.1%. The proportion of patients with favourable outcomes receiving the control regimen was 47.3% (35/74), which was significantly lower than that in the clofazimine group (p 0.034, relative risk 0.661, 95% CI 0.243-0.949).

CONCLUSIONS

The addition of clofazimine to the standard regimen improved the treatment of MDR-TB.

Trends in drug-resistant tuberculosis in China: data from a clinical tuberculosis centre

OBJECTIVE

To describe the trends in prevalence of drug-resistant tuberculosis (TB) among in-patients in Beijing Chest Hospital, Beijing, China, using a 10-year retrospective study.

DESIGN

From 2005 to 2014, 18 310 in-patients with TB were recruited for the study, most of whom were referrals; no distinction was made between new and previously treated cases. Drug susceptibility testing (DST) was performed in culture-positive cases using the proportion method to determine multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB). Risk factors associated with drug resistance were identified.

RESULTS

A total of 5141 (28.0%) samples were culture-positive. DST results showed that 860 (16.7%) cases were MDR-TB and 176 (3.4%) were XDR-TB. MDR-TB and XDR-TB were detected in respectively 21.2% and 12.5% of new cases. The rate of MDR-TB and XDR-TB gradually increased from 2005, with MDR-TB reaching a peak in 2008 and XDR-TB in 2009. These data closely mirror national survey data on this region, patient age and occupation.

CONCLUSION

Trends in MDR-TB and XDR-TB prevalence during the past decade and their inflection points were determined, which complemented reports from previous national surveys. This information is useful for fighting TB in China.

A novel HLA-B allele, HLA-B*40:245 was identified in a patient with hepatitis B virus infection

A novel allele HLA-B*40:245 was discovered in a hepatitis B virus (HBV) infected patient.

Dendritic Cells from Rheumatoid Arthritis Patient Peripheral Blood Induce Th17 Cell Differentiation via miR-363/Integrin αv/TGF-β Axis

Dendritic cells (DCs) are critical regulators of immune responses. This study was to observe the effect of DCs from peripheral blood on the differentiation of Th17 in patients with rheumatoid arthritis (RA). Peripheral blood samples were collected from 30 patients with RA and 20 healthy controls, respectively. Flow cytometry results showed that in contrast to Treg cells, the proportion of Th17 cells in T cells and the Th17/Treg ratio were both increased in patients with RA. The RT-PCR results showed that Foxp3、ROR γt and miR-363 expression in PBMC of patients with RA were reduced, but the ITGAV expression was increased, which was negatively related to miR-363 expression. IL-17, TGF-β and IL-6 levels detected by ELISA were increased in peripheral blood serum of patients with RA. Moreover, we noted that the CD11C⁺ αν⁺ /CD11C⁺ DCs ratio was obvious increased in patients with RA and has positive correlation to the Th17/Treg ratio. In cocultured system, Th17 cell differentiation was significantly inhibited in the presence of ITGF-β suggesting that Th17 cell differentiation was controlled by active TGF-β (aTGF-β). After DCs transfecting with miR-363 mimics and cocultured with T cells, Th17 cell number, IL-17 level and ROR-γt expression were significantly reduced in the presence of latent TGF-β (ITGF-β). In addition, the integrin αv protein expression was both reduced in the presence of aTGF-β or ITGF-β. These data demonstrated that DCs induced Th17 cell differentiation through miR-363/Integrin αv/TGF-β pathway in patients with RA.

Role of levothyroxine and vitamin E supplementation in the treatment of oxidative stress-induced injury and apoptosis of myocardial cells in hypothyroid rats

OBJECTIVE

To explore the underlying mechanism and treatment of myocardial injury caused by hypothyroidism, we evaluated oxidative stress in serum and myocardial tissue of hypothyroid rats. The effect of levothyroxine (LT4) replacement therapy and vitamin E (VitE) supplementation on oxidative stress-induced injury and apoptosis of myocardial tissue is examined.

METHODS

Male Sprague-Dawley rats were divided into five groups: normal control group, propylthiouracil group (PTU group), LT4 treatment group (PTU + LT4 group), vitamin E treatment group (PTU + VitE group), and combined treatment group (PTU + LT4 + VitE group). Superoxide dismutase (SOD) activity and malondialdehyde (MDA) expression in serum and myocardium were determined. Myocardial apoptosis index (AI) in each group was determined by TUNEL assay.

RESULTS

SOD levels in serum were significantly increased in PTU + VitE and PTU + LT4 + Vit E groups, as compared to that in PTU and PTU + LT4 groups (P < 0.05). MDA levels in serum and myocardial tissue were significantly lower in PTU + LT4, PTU + VitE, and PTU + LT4 + VitE groups, as compared to that in the PTU group (P < 0.05). Myocardial apoptosis was significantly increased in PTU and PTU + VitE groups as compared to that in the normal control group (P < 0.05), while it was significantly lower in PTU + LT4 and PTU + LT4 + VitE groups, as compared to that in the PTU group (P < 0.05).

CONCLUSION

In this study, levothyroxine replacement therapy and vitamin E supplementation appeared to ameliorate myocardial apoptosis in hypothyroid rats, the mechanism of which appears to be related to improved thyroid function and reduced oxidative stress.