Prevalence of hypertension in endemic and non-endemic areas of Keshan disease: A cross-sectional study in rural areas of China.

Background: Hypertension is a major public health concern that strongly influences the quality of life of people worldwide. Keshan disease (KD) is an endemic cardiomyopathy related to low selenium, threatening residents in rural areas of 16 provinces in China. Furthermore, the prevalence of hypertension in the KD-endemic areas has been increasing annually. However, hypertension research associated with KD has only focused on endemic regions, and no studies have compared hypertension prevalence between endemic and non-endemic areas. Therefore, this study investigated the prevalence of hypertension to provide a basis for preventing and controlling hypertension in the KD-endemic areas, even in rural areas. Methods: We extracted blood pressure information from cardiomyopathy investigation data from a cross-sectional study of the KD-endemic and non-endemic areas. The hypertension prevalence between the two groups was compared using the Chi-square test or Fisher s exact test. Additionally, Pearson's correlation coefficient was employed to evaluate the relationship between the per capita gross domestic product (GDP) and hypertension prevalence. Results: There was a statistically significant increase of hypertension prevalence in the KD-endemic areas (22.79%, 95% confidence interval [CI]: 22.30-23.27%) over the non-endemic areas (21.55%, 95% CI: 21.09-22.02%). In the KD-endemic areas, more men had hypertension than women (23.90% vs. 21.65%, P < 0.001). Furthermore, the hypertension prevalence was higher in the north than in the south in the KD-endemic areas (27.52% vs. 18.76%, P < 0.001), non-endemic areas (24.86% vs. 18.66%, P < 0.001), and overall (26.17% vs. 18.68%, P < 0.001). Finally, the prevalence of hypertension positively correlated with per capita GDP at province level. Conclusions: The increasing hypertension prevalence is a public health problem in the KD-endemic areas. Healthy diets, such as high consumption of vegetables and seafoods, and foods that are rich in selenium, might help prevent and control hypertension in the KD-endemic areas and other rural areas in China.

Anisotropy of impact ionization in WSe2 field effect transistors.

Carrier multiplication via impact ionization in two-dimensional (2D) layered materials is a very promising process for manufacturing high-performance devices because the multiplication has been reported to overcome thermodynamic conversion limits. Given that 2D layered materials exhibit highly anisotropic transport properties, understanding the directionally-dependent multiplication process is necessary for device applications. In this study, the anisotropy of carrier multiplication in the 2D layered material, WSe2, is investigated. To study the multiplication anisotropy of WSe2, both lateral and vertical WSe2 field effect transistors (FETs) are fabricated and their electrical and transport properties are investigated. We find that the multiplication anisotropy is much bigger than the transport anisotropy, i.e., the critical electric field (ECR) for impact ionization of vertical WSe2 FETs is approximately ten times higher than that of lateral FETs. To understand the experimental results we calculate the average energy of the carriers in the proposed devices under strong electric fields by using the Monte Carlo simulation method. The calculated average energy is strongly dependent on the transport directions and we find that the critical electric field for impact ionization in vertical devices is approximately one order of magnitude larger than that of the lateral devices, consistent with experimental results. Our findings provide new strategies for the future development of low-power electric and photoelectric devices.

Integrative analysis of multiomics data identifies selenium-related gene ALAD associating with keshan disease.

Keshan disease is an endemic fatal dilated cardiomyopathy that can cause heart enlargement, heart failure, and cardiogenic death. Selenium deficiency is considered to be the main cause of Keshan disease. However, the molecular mechanism underlying Keshan disease remains unclear. Our whole-exome sequencing from 68 patients with Keshan disease and 100 controls found 199 candidate genes by gene-level burden tests. Interestingly, using multiomics data, the selenium-related gene ALAD (δ-aminolevulinic acid dehydratase) was the only candidate causative gene identified by three different analysis approaches. Based on single-cell transcriptome data, ALAD was highly expressed in cardiomyocytes and double mutations of human ALAD dramatically reduced its enzyme activity in vitro compared to negative control. Functional analysis of ALAD inhibition in mice resulted in a Keshan phenotype with left ventricular enlargement and cardiac dysfunction, whereas administration of sodium selenite markedly reversed the changes caused by ALAD inhibition. In addition, sodium selenite reversed Keshan phenotypes by affecting energy metabolism and mitochondrial function in mice as shown by the transcriptomic and proteomic data and the ultrastructure of cardiac myocytes. Our findings are the first to demonstrate that the selenium-related gene ALAD is essential for cardiac function by maintaining normal mitochondrial activity, providing strong molecular evidence supporting the hypothesis of selenium deficiency in Keshan disease. These results identified ALAD as a novel target for therapeutic intervention in Keshan disease and Keshan disease-related dilated cardiomyopathy.

A steep switching WSe2 impact ionization field-effect transistor.

The Fermi-Dirac distribution of carriers and the drift-diffusion mode of transport represent two fundamental barriers towards the reduction of the subthreshold slope (SS) and the optimization of the energy consumption of field-effect transistors. In this study, we report the realization of steep-slope impact ionization field-effect transistors (I2FETs) based on a gate-controlled homogeneous WSe2 lateral junction. The devices showed average SS down to 2.73 mV/dec over three decades of source-drain current and an on/off ratio of ~106 at room temperature and low bias voltages (<1 V). We determined that the lucky-drift mechanism of carriers is valid in WSe2, allowing our I2FETs to have high impact ionization coefficients and low SS at room temperature. Moreover, we fabricated a logic inverter based on a WSe2 I2FET and a MoS2 FET, exhibiting an inverter gain of 73 and almost ideal noise margin for high- and low-logic states. Our results provide a promising approach for developing functional devices as front runners for energy-efficient electronic device technology.

Single-Crystalline Pyramidal TiCx Particles Grown by Biphase Diffusion Synthesis.

In this study, we present single-crystalline pyramid-shaped (SP) TiCx particles synthesized on a stacked melt (copper)-solid (titanium) substrate using a biphase diffusion synthesis (BDS) method, in which different sizes ranging from nano- to micrometer scale were obtained within the copper melt with the {100} planes exposed to air. Direct observation and further plasma treatment of the pyramids at different self-assembly stages facilitated the investigation of their growth mode, especially in the horizontal plane. The dendritic growth mode along with the edge and corner-shared modes of the SP TiCx particles frozen on the copper surface was investigated. With SP TiCx particles stacked on top, MoS2-based phototransistors exhibited an up to 6-fold photocurrent increase under laser illumination at different wavelengths, which was attributed to the localized surface plasmonic resonance (LSPR) effect. The BDS method is applied for the synthesis of SP TiCx particles, with a detailed investigation of the relevant growth mode and related applications, such as decoration for high-performance photodevices.

Cordyceps militaris Modulates Intestinal Barrier Function and Gut Microbiota in a Pig Model.

This study investigated the effects of Cordyceps militaris (CM) on intestinal barrier function and gut microbiota in a pig model. A total of 160 pigs were randomly allocated to either a control group (fed the basal diet) or a CM group (fed the basal diet supplemented with 300 mg/kg CM). CM improved intestinal morphology and increased the numbers of goblet cells and intraepithelial lymphocytes. CM also elevated the expression of zona occluden-1, claudin-1, mucin-2 and secretory immunoglobulin A. Furthermore, the mucosal levels of pro-inflammatory cytokines were downregulated while the levels of anti-inflammatory cytokines were upregulated in the CM group. Mechanistically, CM downregulated the expression of key proteins of the TLR4/MyD88/NF-κB signaling pathway. Moreover, CM altered the colonic microbial composition and increased the concentrations of acetate and butyrate. In conclusion, CM can modulate the intestinal barrier function and gut microbiota, which may provide a new strategy for improving intestinal health.

The epidemiological status, environmental and genetic factors in the etiology of Keshan disease.

Keshan disease (KD) is an endemic cardiomyopathy with myocardial lesions for which the precise etiology has not been determined. It was named after the location where it was first identified: Keshan County in China. KD is mainly distributed in a selenium-deficient zone from northeast to southwest China. In recent years, the incidence and prevalence of KD have significantly decreased. Meanwhile, more knowledge was accumulated about the etiology of KD and recent data indicated that genetic factor was involved. In this review, we will first update an overview of the epidemiological status and the environmental and genetic factors involved in this disease.

Photosensitive Graphene P-N Junction Transistors and Ternary Inverters.

We investigate the electric transport in a graphene-organic dye hybrid and the formation of p-n junctions. In the conventional approach, graphene p-n junctions are produced by using multiple electrostatic gates or local chemical doping, which produce different types of carriers in graphene. Instead of using multiple gates or typical chemical doping, a different approach to fabricate p-n junctions is proposed. The approach is based on optical gating of photosensitive dye molecules; this method can produce a well-defined sharp junction. The potential difference in the proposed p-n junction can be controlled by varying the optical power of incident light. A theoretical calculation based on the effective medium theory is performed to thoroughly explain the experimental data. The characteristic transport behavior of the photosensitive graphene p-n junction opens new possibilities for graphene-based devices, and we use the results to fabricate ternary inverters. Our strategy of building a simple hybrid p-n junction can further offer many opportunities in the near future of tuning it for other optoelectronic functionalities.

Lower Cambrian polychaete from China sheds light on early annelid evolution.

We herein report a fossilized polychaete annelid, Guanshanchaeta felicia gen. et sp. nov., from the Lower Cambrian Guanshan Biota (Cambrian Series 2, stage 4). The new taxon has a generalized polychaete morphology, with biramous parapodia (most of which preserve the evidence of chaetae), an inferred prostomium bearing a pair of appendages, and a bifid pygidium. G. felicia is the first unequivocal annelid reported from the Lower Cambrian of China. It represents one of the oldest annelids among those from other early Paleozoic Lagerstätten including Sirius Passet from Greenland (Vinther et al., Nature 451: 185-188, 2011) and Emu Bay from Kangaroo island (Parry et al., Palaeontology 57: 1091-1103, 2014), and adds to our increasing roll of present-day animal phyla recognized in the early Cambrian Guanshan Biota. This finding expands the panorama of the Cambrian 'explosion' exemplified by the Guanshan Biota, suggesting the presence of many more fossil annelids in the Chengjiang Lagerstätte and the Kaili Biota. In addition, this new taxon increases our knowledge of early polychaete morphology, which suggests that polychaete annelids considerably diversified in the Cambrian.

Preparation of an amperometric sensor for norfloxacin based on molecularly imprinted grafting photopolymerization.

A sensitive amperometric sensor for norfloxacin (NF) was introduced. The receptor layer was prepared by molecularly imprinted photopolymerization of acrylamide and trimethylolpropane trimethacrylate on the surface of a gold electrode. The binding mechanism of the molecularly imprinted polymer was explored by ultraviolet (UV) and infrared (IR) spectroscopy. The chemosensor was characterized by cyclic voltammetry (CV), differential pulse voltammetry (DPV), electrochemical impedance (EI), and scanning electron microscopy (SEM). The electrode prepared by photopolymerization has a better recognition ability to template molecules than that of electropolymerization and NIP. Some parameters affecting sensor response were optimized. Norfloxacin was detected by measurements of an amperometric i-t curve. The linear relationships between current and logarithmic concentration are obtained from 1.0 × 10(-9) to 1.0 × 10(-3) mol L(-1). The detection limit of the sensor was 1.0 × 10(-10) mol L(-1). The proposed method is sensitive, simple, and cheap, and is applied to detect NF in human urine successfully.

[Surfactant-assisted solid-phase synthesis and spectral characterization of silver iodide nanowire bundles].

In the present paper, AgNO3 and KI were used as raw materials synthesize silver iodide nanowire bundles in the condition of nonionic surfactant polyethylene glycol (PEG-400) at room temperature. XRD, TEM and SEM techniques were used to characterize the silver iodide structure and morphology. The results indicated that the product was one-dimensional silver iodide nanowire bundles with diameters of 80-100 nm and lengths of 20 microm, and the length-diameter ratio was greater than 200. In the forming process of silver iodide nanowire bundles, PEG-400 surfactant was used as soft template agent, which induced the product nanocrystalline along a particular direction and directional orderly growth so as to generate nanowire bundles. This method with a simple operation and low cost eliminated the influence of water on the reaction process.

[Determination of the ofloxacin in the biologic samples by fluorescence microscopic imaging technique].

The method of CTMAB-Al(3+)-OFLX ternary complex fluorescence microscopic imaging technique was established for the determination of ofloxacin based on the capillary effect of solvent on solid supports, and the concentration in the serum after the chicken was burdened with ofloxacin tablet, the concentration in the human urines and the percentage composition in the honeies, ofloxacin tablets and eye-drops were measured with satisfaction, respectively. In the presence of pH 9. 50 NH3-NH4Cl buffer solution and PVA-124, CTMAB-Al(3+)-OFLX ternary complex can form a self-ordered ring on the hydrophobic supports with the diameter of 1.63 mm and its ring belt width of 50 microm. When a 0.20 microL droplet was spotted, the fluorescence intensity of the ring had a favorable linear relation (r = 0.999 2) with the drug concentration in the range of 3.30 x 10(-13) - 1.65 x 10(-12) mol x ring(-1) (0.60-2.98 mg x L(-1)) and the limit of detection can reach 4.10 x 10(-15) mol x ring(-1) (7.41 microg x L(-1)) with three times of signal to noise ratio. This method has been applied to the average concentration of ofloxacin in the chicken serum with the recovery of 96.4%-101.2% after two hours of being burdened with ofloxacin tablet. Then the technique was applied to the determination of ofloxacin in the three healthy volunteer's urines after oral administration with recovery of 98.2% - 106.%. It was found that the concentrations of ofloxacin in urines were the highest after three hours of taking medicine; the result was similar to reports in the literature. The residues of ofloxacin in three different honey samples were satisfactorily determined with the recoveries of 98.2% - 106.1%, and RSD was less than 2.3%. The contents of active constituent in tablet samples and eye-drops sample were determined with recoveries of 93.5%-101.5% and 95.8%-104.2%, and RSD was 3.5% and 3.6%, respectively, which were similar to marked values.

[Analysis on variance of common pathogenic bacteria and drug resistance in children in Chengdu area from 2001 to 2006].

OBJECTIVE: To investigate the variance and drug resistance of pathogenic bacteria isolated from children with infectious diseases seen between 2001 and 2006 in Chengdu area. METHODS: A total of 2888 pathogenic bacterial strains isolated from children in Chengdu Children's Hospital from 2001 to 2006 were analyzed. Tests were performed according to the guidelines of National Committee for Clinical Laboratory Standards (NCCLS) of the United States. RESULT: (1) Of the 2888 strains, 1845 (63.9%) were Gram negative bacteria. The main pathogenic bacteria included Escherichia coli (Ec, 718 strain, 24.9%), Hemophilus (H, 476 strain, 16.5%), Streptococcus pneumoniae (Sp, 412 strain, 14.3%), Klebsiella pneumoniae (Kp, 369 strain, 12.8%), Staphylococcus aureus (Sa, 353 strain, 12.2%), Staphylococcus epidermidis (Se, 278 strain, 9.6%), Pseudomonas aeruginosa (Pa, 146 strain, 5.1%) and other non-zymocyte (Onz, 136 strain, 4.7%). (2) The common pathogens found in blood specimen were 158 strain, which included Se (78 strain, 49.4%), Ec (23 strain, 14.6%), Kp (17 strain, 10.8%), Sa (14 strain, 8.9%), Onz (14 strain, 8.9%), Sp (7 strain, 4.4%) and Pa (5 strain, 3.2%). (3) The number of common pathogens isolated from patients with lower respiratory tract infection was 2018, including Ec (441 strains, 21.9%), H (430 strains, 21.3%), Sp (368 strains, 18.2%), Kp (253 strains, 12.5%), Sa (207 strains, 10.3%), Se (149 strains, 7.3%), Pa (97 strains, 4.8%) and Onz (73 strains, 3.6%). (4) There were 120 strains of common pathogens isolated from urine specimens, including Ec (78 strains, 65%), Kp (25 strains, 20.8%), Onz (7 strains, 5.8%), Pa (5 strains, 4.2%) and Se (5 strains, 4.2%). (5) There were 497 strains of common pathogens found in pus specimens, including Ec 167 strains, (33.6%), Sa (126 strains, 25.4%), Se (46 strains, 9.3%), H (44 strains, 8.9%), Onz (37 stains, 7.4%), Kp (31 strains, 6.2%), Sp (26 strains, 5.2%) and Pa (20 strain, 4.0%). The trend of drug resistance of pathogenic bacteria to antibiotics deteriorated. The proportion of methicillin-resistant Staphylococcus aureus (MRSA) was 6.7% and the methicillin-resistant coagulase-negative Staphylococci (MRCNS) rate was 20% in 2001 - 2003. The total proportion of extended-spectrum beta-lactamase stains (ESBL(S)) in Ec and Kp was 21.8%, and the rate of beta-lactamase production stains of Hemophilus influenzae (Hi) was 19.4% in 2001 - 2003.The proportion of MRSA was 17.2% and the MRCNS rate was 70.2%, the total proportion of ESBL(S) in Ec and Kp was 43.8%, and the rate of beta-lactamase producing stains of Hi was 39.7% in 2004 - 2006. CONCLUSION: The distribution of common pathogenic bacteria seen in Chengdu Children's Hospital has changed and the trend of drug resistance of pathogenic bacteria to antibiotics deteriorated in recent three years. Regionally monitoring the changes in pathogenic bacteria and the trend of drug resistance to antibiotics is paramount in guiding the pediatric clinical treatment.

Determination of aspartate and glutamate in rabbit retina using polymer monolith microextraction coupled to high-performance liquid chromatography with fluorescence detection.

A simple, sensitive and low-cost method was developed for the determination of aspartate (Asp) and glutamate (Glu) in rabbit retina. Polymer monolith microextraction (PMME) using a poly(acrylamide-vinylpyridine-N,N'-methylene bisacrylamide) (AA-VP-Bis) monolithic column was combined with derivatization of Asp and Glu using 8-phenyl-(4-oxy-acetic acid N-hydroxysuccinimide ester)-4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene (TMPAB-OSu), and this was used to analyze the derivatives of Asp and Glu by high-performance liquid chromatography (HPLC) with fluorescence detection. The conditions for the derivatization and the subsequent extraction of Asp and Glu derivatives were optimized. The enrichment factors for the derivatives of Asp and Glu were found to be 14.1 and 14.7, respectively, by PMME. The limits of detection of Asp and Glu were 0.14 and 0.53 nmol/L, respectively. The precision and recovery were evaluated with spiked retina. The inter- and intraday relative standard deviations were less than 10%. The proposed method was successfully applied to the determination of Asp and Glu levels in rabbit retina samples with different stages of intraocular hypertension.

Determination of biogenic amines in apples and wine with 8-phenyl-(4-oxy-acetic acid N-hydroxysuccinimide ester)-4, 4-difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene by high performance liquid chromatography.

A precolumn-derivatization high performance liquid chromatographic method for biogenic amine analysis has been developed. Derivatization of biogenic amines was performed with a new fluorescent reagent, 8-phenyl-(4-oxy-acetic acid N-hydroxysuccinimide ester)-4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene (TMPAB-OSu), which was synthesized in our lab. The derivatization conditions and the influence of elution composition on the separation were investigated. In pH 8.5 H3BO3-Na2B4O7 media, the reaction of biogenic amines with TMPAB-OSu completed at 45 degrees C for 5 min. The labeled biogenic amines were separated on an ZORBAX Eclipse XDB-C8 column (150 mm x 4.6 mm, 5 microm) and detected with fluorescence at excitation and emission wavelengths of 497 and 509 nm, respectively. Detection limits of biogenic amines were 0.1-4 nmol L(-1), at a signal-to-noise ratio of 3. The proposed method has been applied to the quantitative determination of spermine, phenethylamine, spermidine, cadaverine and putrescine in pericarp and pulp of mature and immature apples and wine with recoveries of 95-102% and R.S.D. of 0.7-3.9.

8-Phenyl-(4-oxy-acetic acid N-hydroxysuccinimidyl ester)-4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene as a new highly fluorescent-derivatizing reagent for aliphatic amines in disease-related samples with high-performance liquid chromatography.

A novel fluorescent-activated ester, 8-phenyl-(4-oxy-acetic acid N-hydroxysuccinimidyl ester)-4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene (TMPAB-OSu) has been designed and synthesized for amine labeling in HPLC. Being used 11 aliphatic amines as the models, the derivatization conditions were optimized. In 0.2 mol/l borate buffer (pH 8.8), amines reacted with TMPAB-OSu at 30 degrees C to form the derivatives in 10 min. The fluorescent quantum yield of TMPAB-OSu and its amine derivatives are high even compared with fluorescein. The separation of these amine derivatives was achieved with a C(8) column and gradient elution by using 0.1 mol/l sodium acetate buffer (pH 5.0) and methanol. With fluorescence detection at an emission wavelength of 509 nm and an excitation wavelength of 497 nm, the detection limits of aliphatic amines were 2-18 fmol, at a signal-to-noise ratio of 3:1. The proposed TMPAB-OSu-based HPLC method has been applied to the analysis of urine samples of health, hepatic and renal patients and lake water. Recoveries from different matrices are from 96 to 104%, depending on the sample investigated.

6-Oxy-(N-succinimidyl acetate)-9-(2'-methoxycarbonyl)fluorescein as a new fluorescent labeling reagent for aliphatic amines in environmental and food samples using high-performance liquid chromatography.

6-Oxy-(N-succinimidyl acetate)-9-(2'-methoxycarbonyl)fluorescein (SAMF), a new fluorescein-based amine-reactive fluorescent probe was well designed, synthesized and used as a pre-column derivatizing reagent for the determination of aliphatic amines in HPLC. It exhibited relatively pH-independent fluorescence (pH 4-9) and excellent photostability. The derivatization was performed at room temperature in 6min. On a C18 column, the derivatives of SAMF with eight aliphatic amines were baseline separated in 28 min with a mobile phase of methanol-water (57:43, v/v) containing 10 mmol l(-1) pH 5.0, H3Cit3-NaOH buffer. With fluorescent detection at lambda(ex)/lambda(em) = 484/516 nm, the detection limit could reach 2-320 fmol (signal-to-noise = 3), which was equivalent to or better than the detection limits obtained from other analytical methods of aliphatic amines. The proposed method has been applied to the determination of the aliphatic amines in environmental and food samples such as lake water, red wine, white wine, and cheese with satisfying recoveries varying from 95 to 106%.

Spectrofluorimetric determination of total amount of nitrite and nitrate in biological sample with a new fluorescent probe 1,3,5,7-tetramethyl-8-(3',4'-diaminophenyl)-difluoroboradiaza-s-indacence.

A new synthesized fluorescent probe, 1,3,5,7-tetramethyl-8-(3',4'-diaminophenyl)-difluoroboradiaza-s-indacence (TMDABODIPY), has been used to detect nitrite. When TMDABODIPY reacted with nitrite, a weak fluorescent triazole formed in 0.2 mol l(-1) HCl medium at room temperature. The fluorescence quenching intensity was linear over a nitrite concentration of 0.04-0.32 mumol l(-1) with a detection limit of 0.3 nmol l(-1) (S/N=3). The proposed method has been applied to the determination of total amount of nitrite and nitrate (reduced by Zn powder) in human serum and urine of health and hypertension persons with recoveries of 91.83-101.80%.