Electronic Properties and Electrocatalytic Water Splitting Activity for Precious-Metal-Adsorbed Silicene with Nonmetal Doping.

Since nonmetal (NM)-doped two-dimensional (2D) materials can effectively modulate their physical properties and chemical activities, they have received a lot of attention from researchers. Therefore, the stability, electronic properties, and electrocatalytic water splitting activity of precious-metal (PM)-adsorbed silicene doped with two NM atoms are investigated based on density functional theory (DFT) in this paper. The results show that NM doping can effectively improve the stability of PM-adsorbed silicene and exhibit rich electronic properties. Meanwhile, by comparing the free energies of the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) intermediates of 15 more stable NM-doped systems, it can be concluded that the electrocatalytic water splitting activity of the NM-doped systems is more influenced by the temperature. Moreover, the Si-S2-Ir-doped system exhibits good HER performance when the temperature is 300 K, while the Si-N2-Pt-doped system shows excellent OER activity. Our theoretical study shows that NM doping can effectively promote the stability and electrocatalytic water splitting of PM-adsorbed silicene, which can help in the application of silicene in electrocatalytic water splitting.

Recombination between NADC34-like and QYYZ-like strain of porcine reproductive and respiratory syndrome virus with high pathogenicity for piglets in China.

Porcine reproductive and respiratory syndrome virus (PRRSV) is an important pathogen that causes huge economic losses to the swine industry worldwide. Here, a novel variant of PRRSV strain named TJnh2021 was isolated from nursery piglets with morbidity rate (75%) and mortality rate (40%) in Tianjin Province of China in 2021. Phylogenetic and molecular evolutionary analyses revealed that TJnh2021 was highly similar to NADC34-like (lineage 1.5, isolated in North America in 2014) in the ORF1ab-ORF2 and ORF6-ORF7 coding regions, as well as to QYYZ-like (lineage 3, isolated in China in 2010) in the ORF3-ORF5, suggestive of a natural recombination event. Recombination analyses revealed that recombination events occurred in two interlineage recombination events between lineages 1.5 and 3, and two breakpoints in ORF2 (nt12196) and ORF5 (nt13628) (with reference to the VR-2332 strain). Animal experiments demonstrated that TJnh2021 caused mortality rates of 40% and exhibited higher pathogenicity in piglets compared to other lineage 1.5 strains reported in China. Taken altogether, NADC34-like PRRSV has undergone genetic exchange with Chinese local PRRSV strains and recombination might be responsible for the variations in pathogenicity and highlight the importance of surveillance of this lineage in China.

Topological phase transition and tunable electronic properties of hydrogenated bismuthene: from single-layer to double-layer.

Planar bismuthene grown on SiC substrate provides a promising candidate to engineer van der Waals double-layer (DL) made of two dimensional (2D) topological insulators. We perform systematical calculations in DL hydrogenated bismuthene (H-Bi) that can be used to simulate the experimentally grown planar bismuthene to explore realizable 2D topological insulator van der Waals DL. Two possible geometry configurations of AA- and AB-stacked DL H-Bi are investigated. Due to pseudo Jahn-Teller effect, AB-stacked DL H-Bi has a strong interlayer coupling interaction and shows buckled lattice. Particularly, both AA- and AB-stacked DL H-Bi are topologically trivial rather than topologically nontrivial. The physical origin of the trivial topology is clarified by analyzing orbital composition. We discuss how the electronic properties are modified by interlayer coupling, external strain, and metal atom intercalation. It is also found that, for AB-stacked DL H-Bi, metal atom intercalation gives rise to novel multiple Rashba splitting near the valence band top, which is expected to manipulate the same spin in different planar bismuthene layers. Our results present various and tunable electronic properties of van der Waals DL H-Bi and allow for probing into multiple Rashba effect in 2D inversion-asymmetric topological insulators.

Base-iodine-promoted metal-catalyst-free reactions of [60]fullerene with ß-keto esters for the selective formation of [60]fullerene derivatives.

In this study, methanofullerenes and 2',3'-dihydrofuran C60 derivatives were selectively synthesized in high yields via the reactions of C60 with ß-keto esters under mild conditions by controlling the addition sequence and molar ratio of iodine and base. The structures of the products were determined by spectroscopic characterization. Moreover, a possible reaction mechanism for the selective formation of fullerene derivatives was proposed.

[Effects of Early Enteral Immunonutrition on Postoperative Immune Function and Rehabilitation of Patients with Gastric Cancer and Nutritional Risk].

OBJECTIVES: To investigate the effects of early enteral immunonutrition on postoperative immune function and rehabilitation of gastric cancer patients with nutritional risk. METHODS: New hospitalized patients with gastric cancer were evaluated the nutrient status based on NRS 2002. The patients who scored between 3 to 5 points were randomized into two groups(30 cases for each group), and those in experimental group were given 7-d early postoperative enteral immune nutrition, those in control group were given normal nutrition. The immune indexes (CD3+, CD4+, CD8+ and CD4+/CD8+) and nutritional indexes(transferrin, pre-albumin, albumin) were measured before operation and at the 3rd and 7th day postoperatively. In addition, the first flatus time, gastrointestinal adverse reactions and complications, length of hospital stays were compared between the two groups. RESULTS: The level of CD4+/CD8+ and transferrin, pre-albumin, albumin in experimental group were significantly higher than those in control group at the third and seventh day postoperatively (P<0.05).Compared with the control group, the experimental group had shorter first flatus time after surgery, which were (63.5±7.3) h vs. (72.8±8.6 ) h respectively (P<0.05).There were no statistically difference on pneumonia, anastomosis leakage, severe abdominal distension, inflammatory bowel obstruction and total postoperative hospitalization time between the two groups (P>0.05). CONCLUSIONS: Early enteral immunonutrition can effectively promote the recovery of nutritional status and immune function in gastric cancer patients with nutrition risk.

GATA-1 directly regulates Nanog in mouse embryonic stem cells.

Nanog safeguards pluripotency in mouse embryonic stem cells (mESCs). Insight into the regulation of Nanog is important for a better understanding of the molecular mechanisms that control pluripotency of mESCs. In a silico analysis, we identify four GATA-1 putative binding sites in Nanog proximal promoter. The Nanog promoter activity can be significantly repressed by ectopic expression of GATA-1 evidenced by a promoter reporter assay. Mutation studies reveal that one of the four putative binding sites counts for GATA-1 repressing Nanog promoter activity. Direct binding of GATA-1 on Nanog proximal promoter is confirmed by electrophoretic mobility shift assay and chromatin immunoprecipitation. Our data provide new insights into the expanded regulatory circuitry that coordinates Nanog expression.

Hesx1 enhances pluripotency by working downstream of multiple pluripotency-associated signaling pathways.

Hesx1, a homeobox gene expressed in embryonic stem cells (ESCs), has been implicated in the core transcription factors governing the pluripotent state. However, data about the underlying mechanism of how Hesx1 is involved in maintaining pluripotency is still scarce. In this study, we find Hesx1 responds to multiple pluripotency-related pathway inhibitors as well as LIF stimulation. Particularly, the expression of Hesx1 can be readily induced by dual inhibition (2i) of glycogen synthase kinase 3 and mitogen-activated protein kinase. Forced expression of Hesx1 can partially compensate for the withdrawal of either LIF or each component of 2i. We also demonstrate that LIF and each inhibitor of 2i can induce Hesx1 independent of one another. We tentatively put forward that Hesx1 is a common downstream target of LIF- and 2i-mediated self-renewal signaling pathways and plays an important role in maintaining ESC identity. Our study extends the methods of identifying the missing crucial factors in establishing ESC pluripotency.

Calibrating the end-Permian mass extinction.

The end-Permian mass extinction was the most severe biodiversity crisis in Earth history. To better constrain the timing, and ultimately the causes of this event, we collected a suite of geochronologic, isotopic, and biostratigraphic data on several well-preserved sedimentary sections in South China. High-precision U-Pb dating reveals that the extinction peak occurred just before 252.28 ± 0.08 million years ago, after a decline of 2 per mil (‰) in δ(13)C over 90,000 years, and coincided with a δ(13)C excursion of -5‰ that is estimated to have lasted ≤20,000 years. The extinction interval was less than 200,000 years and synchronous in marine and terrestrial realms; associated charcoal-rich and soot-bearing layers indicate widespread wildfires on land. A massive release of thermogenic carbon dioxide and/or methane may have caused the catastrophic extinction.

Trends of case detection and other indicators of leprosy in China during 1985-2002.

OBJECTIVE: To analyze the trends of case detection and other indicators of leprosy in China during 1985-2002. METHODS: Data reported by each province were collected by China National Leprosy Database in Nanjing P.R. China. All data about registered cases were put into computer for analysis. RESULTS: From 1985 to 2002, a total of 49,477 new leprosy cases had been detected. Among them, 69.5% were multibacillary cases and 25.4% had grade 2 disability. The child cases aged below 15 years accounted for 3.74% of total cases. Totally, 5824 cases and 303 cases relapsed after dapsone (DDS) mono-therapy and multidrug therapy (MDT), respectively. Case detection showed a marked reduction from 0.47/100,000 in 1985 to 0.18/100,000 in 1993 although there were several spurts due to operational factors. From 1994, case detection showed no significant decline. The grade 2 disability among new patients decreased from 31.4% in 1985 to 23.4% in 2002. The child case detection rate among new cases fluctuated between 2.70%-3.56% from 1999 to 2002. The incidence of relapse declined after the introduction of DDS mono-therapy. However, it increased after the introduction of MDT. CONCLUSION: China experiences in leprosy control show that it will take a long time with continuing present leprosy control activities to bring down the case detection and other indicators to a very low level even after reaching the elimination goal of leprosy.

[Polymorphisms within the interferon-Gamma receptor associated with systemic lupus erythematosus].

OBJECTIVE: To assess the association between polymorphisms within the interferon-Gamma receptor gene(IFN-GammaR) and systemic lupus erythematosus (SLE) in Chinese people. METHODS: The IFN-GammaR genotypes of 94 SLE patients and 80 healthy subjects were examined by the reverse transcription-polymerase chain reaction (RT-PCR)-single-strand conformation polymorphism (SSCP) method, RT-PCR-restriction fragment length polymorphism (RFLP) method and DNA sequencing. RESULTS: There was no statistically significant difference in the IFN-GammaR genotype frequencies between the two groups. The IFN-Gamma R2 Arg64/Arg64 genotype decreased the risk of SLE (OR = 2.481, 95% CI 0.992 - 6.203, P = 0.047). The decreased risk of the development of SLE was detected in the individuals who had the combination of IFN-GammaR2 Arg64/Arg64 genotype and IFN-GammaR1 Val14/Val14 genotype (OR = 2.481, 95% CI 0.992 - 6.203, P = 0.047). CONCLUSION: The IFN-GammaR2 Arg64/Arg64 genotype does not determine susceptibility to SLE in Chinese people, and the combination of IFN-Gamma R2 Arg64/Arg64 genotype and IFN-Gamma R1 Val14/Val14 genotype does not, either.

[Treating metastatic vertebral tumor with percutaneous vertebroplasty: a report of 28 cases].

BACKGROUND & OBJECTIVE: Treating metastatic vertebral tumor is a common difficulty. Conservative treatment can't efficiently release the pain, and establish the spinal column; while operation may destroy normal tissue, and cause many complications, which would prolong the time of in-hospital, and delay the treatment of primary disease, at the same time, operation is not suitable for multiple metastatic spinal tumors. This study was designed to investigate the efficacy of percutaneous vertebroplasty (PVP) on metastatic spinal tumor under the guidance of digital subtraction angiography (DSA). METHODS: A total of 58 patients with metastatic spinal tumor were divided into 2 groups according to their intention, 28 (group A) were treated with PVP combined radiochemotherapy, 30 (group B) were treated with routine radiochemotherapy. Baselines of the 2 groups have no significant difference. Two months after treatment, the life quality, therapeutic response, stabilization of the vertebral column, and toxic effect were compared between group A and group B. RESULTS: After treatment, both groups showed significant changes in life quality, and therapeutic response (P < 0.05, t(1)=2.74, t(2)=11.74). Group A showed no complication. Group B showed 5 cases of pathologic constrictive fracture in spinal body. CONCLUSION: PVP is a simple and minimally invasive treatment with few complications, which can release pain, decrease incidence of pathologic constrictive fracture in spinal body, and improve life quality of patients with metastatic spinal tumor.

Studies on risk of leprosy relapses in China: relapses after treatment with dapsone monotherapy

Based upon the data from the Chinese National System for Leprosy Surveillance, this paper reports on the relapses in 297,343 leprosy patients [multibacillary (MB) 106,518, paucibacillary (PB) 190,825] cured by dapsone monotherapy. A total of 11,055 (MB 8675, PB 2380) patients relapsed during an accumulated follow-up period of 4,229,050 patient-years (PY), giving an overall relapse rate of 3.72 per 100 cases or 2.61 per 1000 PY, i.e., 8.14% or 5.91 per 1000 PY over an average follow-up period of 13.8 +/- 8.4 years in MB patients and 1.25% or 0.86 per 1000 PY over an average period of 14.5 +/- 8.9 years in PB patients. For either the overall relapse rate per 100 cases or per 1000 PY, the differences between MB and PB patients were statistically significant, except during 36-40 years of follow up. For both MB and PB patients, the relapse rates showed consistently significant decreases year by year, particularly in PB patients whose relapse rate per 1000 PY was 1.21 in year 10 of follow up; whereas it remained more than 10 per 1000 PY in MB patients. In view of that, the overall relapse rates in MB and PB patients cured by dapsone monotherapy were acceptably low, and most of these patients have been followed up for more than a mean incubation period of observed dapsone relapse. Along with the further extension of follow up, the risk of relapse in dapsone-cured patients will not be expected to increase. This conclusion should be considered when planning policy for the management of patients released from dapsone monotherapy.