Oscillatory thermopower of carbon chains: First-principles calculations

We investigate the thermoelectric transport through carbon chains connected by two Al leads. Using a Landauer-Buttiker-like formula, we calculate the thermopower and thermoconductance of Al-Cn-Al from first principles. We find that the charge transfer plays an important role in the thermoelectric transport. Because of the charge transfer, the thermopower changes sign for even-odd number of carbon atoms. The thermopower and electric conductance as a function of the gate voltage also exhibit oscillatory behaviors with a phase difference of pi/2.published_or_final_versio

Spin pump in the presence of a superconducting lead

We present a theoretical analysis of a spin pump in the presence of a superconducting lead. The spin pump is facilitated by a rotating magnetic field which provides a spin flip mechanism and hence can generate a spin current without an accompanying charge current. Using a nonequilibrium Green's function method, we obtain a general solution of the pumped charge current and spin current in both the adiabatic and non-adiabatic regimes. The numerical results for the charge current and spin current are presented as we vary different system parameters such as the gate voltage, the external magnetic field, and the pumping frequency. We find that for a quantum dot with a single resonant level in line with the Fermi energy of the left normal lead, a pure spin current is generated by a rotating magnetic field at any frequency. We have identified two kinds of photon-assisted processes which dominate at low pumping frequencies and high pumping frequencies, respectively.published_or_final_versio

A Novel Antioxidant Multitarget Iron Chelator M30 Protects Hepatocytes against Ethanol-Induced Injury

published_or_final_versio

Antioxidant treatment enhances human mesenchymal stem cell anti-stress ability and therapeutic efficacy in an acute liver failure model

published_or_final_versio

The focusing effect of electron flow and negative refraction in three-dimensional topological insulators

published_or_final_versio

Influence of magnetic disorders on quantum anomalous Hall effect in magnetic topological insulator films beyond the two-dimensional limit

published_or_final_versio

Persistent viral shedding of SARS‐CoV‐2 in faeces – a rapid review

Aim In addition to respiratory symptoms, COVID‐19 can present with gastrointestinal complaints suggesting possible faeco‐oral transmission. The primary aim of this review was to establish the incidence and timing of positive faecal samples for SARS‐CoV‐2 in patients with COVID‐19. Methods A systematic literature review identified studies describing COVID‐19 patients tested for faecal virus. Search terms for MEDLINE included ‘clinical’, ‘faeces’, ‘gastrointestinal secretions’, ‘stool’, ‘COVID‐19’, ‘SARS‐CoV‐2’ and ‘2019‐nCoV’. Additional searches were done in the American Journal of Gastroenterology , Gastroenterology , Gut , Lancet Gastroenterology and Hepatology , the World Health Organization Database, the Centre for Evidence‐Based Medicine, New England Journal of Medicine , social media and the National Institute for Health and Care Excellence, bioRxiv and medRxiv preprints. Data were extracted concerning the type of test, number and timing of positive samples, incidence of positive faecal tests after negative nasopharyngeal swabs and evidence of viable faecal virus or faeco‐oral transmission of the virus. Results Twenty‐six relevant articles were identified. Combining study results demonstrated that 53.9% of those tested for faecal RNA were positive. The duration of faecal viral shedding ranged from 1 to 33 days after a negative nasopharyngeal swab with one result remaining positive 47 days after onset of symptoms. There is insufficient evidence to suggest that COVID‐19 is transmitted via faecally shed virus. Conclusion There is a high rate of positive polymerase chain reaction tests with persistence of SARS‐CoV‐2 in faecal samples of patients with COVID‐19. Further research is needed to confirm if this virus is viable and the degree of transmission through the faeco‐oral route. This may have important implications on isolation, recommended precautions and protective equipment for interventional procedures involving the gastrointestinal tract

Clinical characteristics of the autumn-winter type scrub typhus cases in south of Shandong province, northern China

<p>Abstract</p> <p>Background</p> <p>Before 1986, scrub typhus was only found endemic in southern China. Because human infections typically occur in the summer, it is called "summer type". During the autumn-winter period of 1986, a new type of scrub typhus was identified in Shandong and northern Jiangsu province of northern China. This newly recognized scrub typhus was subsequently reported in many areas of northern China and was then called "autumn-winter type". However, clinical characteristics of associated cases have not been reported.</p> <p>Methods</p> <p>From 1995 to 2006, all suspected scrub typhus cases in five township hospitals of Feixian county, Shandong province were enrolled. Indirect immunofluorescent assay (IFA) was used as confirmatory serodiagnosis test. Polymerase chain reaction (PCR) connected with restriction fragment length polymorphism (RFLP) and sequence analyses were used for genotyping of <it>O. tsutsugamushi </it>DNAs. Clinical symptoms and demography of confirmed cases were analyzed.</p> <p>Results</p> <p>A total of 480 scrub typhus cases were confirmed. The cases occurred every year exclusively between September and December with a peak occurrence in October. The case numbers were relatively higher in 1995, 1996, 1997, and 2000 than in other years. 57.9% of cases were in the group aged 21–50. More cases occurred in male (56%) than in female (44%). The predominant occupational group of the cases was farmers (85.0%). Farm work was reported the primary exposure to infection in 67.7% of cases. Fever, rash, and eschar were observed in 100.0%, 90.4%, and 88.5% of cases, respectively. Eschars formed frequently on or around umbilicus, abdomen areas, and front and back of waist (34.1%) in both genders. Normal results were observed in 88.7% (WBC counts), 84.5% (PLT counts), and 89.7% (RBC counts) of cases, respectively. Observations from the five hospitals were compared and no significant differences were found.</p> <p>Conclusion</p> <p>The autumn-winter type scrub typhus in northern China occurred exclusively from September to December with a peak occurrence in October, which was different from the summer type in southern China. In comparison with the summer type, complications associated with autumn-winter type scrub typhus were less severe, and abnormalities of routine hematological parameters were less obvious.</p

Five-Year Follow-Up of Parapapillary Atrophy: The Beijing Eye Study

Purpose: To assess longitudinal changes in parapapillary atrophy in the adult population of Greater Beijing. Methods: The population-based Beijing Eye Study 2006 included 3251 subjects who had participated in the Beijing Eye Study 2001 and returned for re-examination. The mean age was 60.4610.1 years. Using optic disc photographs, we measured parapapillary atrophy which was divided into alpha zone and beta zone. Results: Overall progression rate of alpha zone was seen in 0.660.1 % (95 % confidence interval (CI):0.3,0.9) of the subjects and of beta zone in 8.260.5 % (95%CI:7.2,9.1) of the subjects. In binary regression analysis, rate of progression of alpha zone was significantly associated higher age (P = 0.04) and the co-progression of zone Beta (P,0.001). Rate of progression of beta zone was significantly associated with higher age (P,0.001; odds ratio (OR):1.11;95%CI:1.10,1.14), higher intraocular pressure (P,0.001;OR:1.10;95%CI:1.05,1.14), higher myopic refractive error (P,0.001;OR:0.71; 95%CI:0.67,0.75), rural region of habitation (P = 0.002;OR: 0.58; 95%CI:0.41,0.82), presence of glaucomatous optic nerve damage (P,0.001;OR:2.89; 95%CI:1.62,5.14), co-progression of alpha zone (P,0.001;OR:7.13;95%CI:2.43,20.9), absence of arterial hypertension (P = 0.03;OR: 0.70; 95%CI:0.51,0.96), and thicker central corneal thickness (P = 0.02;OR:1.01;95%CI:1.00,1.01). Subjects with a non-glaucomatous optic nerve damage (n = 22) as compared to the remaining subjects did not vary in the progression rate of alpha zone (0.0 % versus 0.660.1%; P = 1.0) and beta zone (8.260.5 % versus 6.360.6%;P = 1.0)

Five Year Incidence of Visual Field Loss in Adult Chinese. The Beijing Eye Study.

PURPOSE: To describe the cumulative 5 year incidence of visual field loss in adult Chinese in Greater Beijing. METHODS: The Beijing Eye Study 2006 included 3251 subjects (mean age 60.4±10.1 years) who had participated in the Beijing Eye Study 2001 and returned for re-examination. All participants underwent a comprehensive eye examination, including visual field test by frequency doubling threshold perimetry. An abnormal visual field was defined as reduced sensitivity in at least one test location. Incident visual field loss was defined as a change in visual field from normal at baseline to abnormal at follow-up. RESULTS: An incident visual field loss was detected in 273 eyes (4.3±0.5%)/235 subjects (7.3±0.5%). It was significantly associated with higher age (P = 0.001), higher intraocular pressure (P<0.001), and higher fasting blood glucose concentration (P = 0.019). Considering only eyes (n = 140) with a detected cause for visual field loss, the most frequent causes were cataract (68 (48.6%) eyes) followed by glaucoma (23 (16.4%) eyes), diabetic retinopathy (13 (9.3%) eyes), age-related macular degeneration (10 (7.1%) eyes), and myopic degenerative retinopathy (9 (6.4%) eyes). For 133 (48.7%) eyes with a visual field loss, the cause for the VFL remained unclear. CONCLUSIONS: The 5-year incidence of visual field loss was 4.3±0.5% per eye or 7.3±0.5% per subject. It increased significantly with age, intraocular pressure, and fasting blood glucose level. Major causes for the incidence of visual field loss were cataract, glaucoma and diabetic retinopathy