Correlation of Key Physiological Properties of Methanosarcina Isolates with Environment of Origin.

It is known that the physiology of Methanosarcina species can differ significantly, but the ecological impact of these differences is unclear. We recovered two strains of Methanosarcina from two different ecosystems with a similar enrichment and isolation method. Both strains had the same ability to metabolize organic substrates and participate in direct interspecies electron transfer but also had major physiological differences. Strain DH-1, which was isolated from an anaerobic digester, used H2 as an electron donor. Genome analysis indicated that it lacks an Rnf complex and conserves energy from acetate metabolism via intracellular H2 cycling. In contrast, strain DH-2, a subsurface isolate, lacks hydrogenases required for H2 uptake and cycling and has an Rnf complex for energy conservation when growing on acetate. Further analysis of the genomes of previously described isolates, as well as phylogenetic and metagenomic data on uncultured Methanosarcina in anaerobic digesters and diverse soils and sediments, revealed a physiological dichotomy that corresponded with environment of origin. The physiology of type I Methanosarcina revolves around H2 production and consumption. In contrast, type II Methanosarcina species eschew H2 and have genes for an Rnf complex and the multiheme, membrane-bound c-type cytochrome MmcA, shown to be essential for extracellular electron transfer. The distribution of Methanosarcina species in diverse environments suggests that the type I H2-based physiology is well suited for high-energy environments, like anaerobic digesters, whereas type II Rnf/cytochrome-based physiology is an adaptation to the slower, steady-state carbon and electron fluxes common in organic-poor anaerobic soils and sediments. IMPORTANCE Biogenic methane is a significant greenhouse gas, and the conversion of organic wastes to methane is an important bioenergy process. Methanosarcina species play an important role in methane production in many methanogenic soils and sediments as well as anaerobic waste digesters. The studies reported here emphasize that the genus Methanosarcina is composed of two physiologically distinct groups. This is important to recognize when interpreting the role of Methanosarcina in methanogenic environments, especially regarding H2 metabolism. Furthermore, the finding that type I Methanosarcina species predominate in environments with high rates of carbon and electron flux and that type II Methanosarcina species predominate in lower-energy environments suggests that evaluating the relative abundance of type I and type II Methanosarcina may provide further insights into rates of carbon and electron flux in methanogenic environments.

Solvent-Induced Assembly of Microbial Protein Nanowires into Superstructured Bundles.

Protein-based electronic biomaterials represent an attractive alternative to traditional metallic and semiconductor materials due to their environmentally benign production and purification. However, major challenges hindering further development of these materials include (1) limitations associated with processing proteins in organic solvents and (2) difficulties in forming higher-order structures or scaffolds with multilength scale control. This paper addresses both challenges, resulting in the formation of one-dimensional bundles composed of electrically conductive protein nanowires harvested from the microbes Geobacter sulfurreducens and Escherichia coli. Processing these bionanowires from common organic solvents, such as hexane, cyclohexane, and DMF, enabled the production of multilength scale structures composed of distinctly visible pili. Transmission electron microscopy revealed striking images of bundled protein nanowires up to 10 µm in length and with widths ranging from 50-500 nm (representing assembly of tens to hundreds of nanowires). Conductive atomic force microscopy confirmed the presence of an appreciable nanowire conductivity in their bundled state. These results greatly expand the possibilities for fabricating a diverse array of protein nanowire-based electronic device architectures.

Renal involvement in a silicosis patient - case report and literature review.

A 43-year-old Chinese man with a silicosis history was admitted to our hospital due to bilateral lower extremity edema for 1 year, exacerbating with hematuria for 2 months. He started working as a coal miner 30 years ago, and was diagnosed as silicosis 3 months ago. Lab tests revealed hematuria 3+, proteinuria 3+, and a serum creatinine value 2.47 mg/dl on routine check. He was diagnosed with focal proliferative IgA nephropathy (IgAN) and acute tubulo-interstitial nephritis by renal biopsy. He was treated with corticosteroids and got a remission 4 months later. Immunohistochemical staining showed the deposition of macrophage receptor with collagenous structure (MARCO), nod-like receptor pyrin domain-containing-3 (NLRP3), Caspase-1, apoptosis-associated speck (ASC), interleukin (IL)-1ß, and IL-18 in both glomerular and tubulo-interstitial areas. We proposed that the silicon exposure could be related to his kidney disease in the patient and NLRP3 mediated inflammation might be involved in its pathogenesis which needs further explorations.

Conductive Composite Materials Fabricated from Microbially Produced Protein Nanowires.

Protein-based electronic materials have numerous potential advantages with respect to sustainability and biocompatibility over electronic materials that are synthesized using harsh chemical processes and/or which contain toxic components. The microorganism Geobacter sulfurreducens synthesizes electrically conductive protein nanowires (e-PNs) with high aspect ratios (3 nm × 10-30 µm) from renewable organic feedstocks. Here, the integration of G. Sulfurreducens e-PNs into poly(vinyl alcohol) (PVA) as a host polymer matrix is described. The resultant e-PN/PVA composites exhibit conductivities comparable to PVA-based composites containing synthetic nanowires. The relationship between e-PN density and conductivity of the resultant composites is consistent with percolation theory. These e-PNs confer conductivity to the composites even under extreme conditions, with the highest conductivities achieved from materials prepared at pH 1.5 and temperatures greater than 100 °C. These results demonstrate that e-PNs represent viable and sustainable nanowire compositions for the fabrication of electrically conductive composite materials.

High YBX1 expression indicates poor prognosis and promotes cell migration and invasion in nasopharyngeal carcinoma.

Y-box binding protein-1 (YBX1) is a multifunctional protein and often acts as an indicator of poor prognosis in cancers. Increasing evidence has shown that the levels of YBX1 protein were closely associated with multidrug resistance, relapse, metastasis and poor prognosis in cancers. However, its role in nasopharyngeal carcinoma (NPC) metastasis remains unknown. In our study, we discovered that the expression of YBX1 was increased in nasopharyngeal carcinoma tissues. YBX1 protein levels positively correlated with T stage and metastasis of NPC patients. Moreover, expression of YBX1 was negatively correlated with membrane E-cadherin levels and positively correlated with Vimentin expression. In vitro, the expression of YBX1 was closely related to the invasive and migratory ability of nasopharyngeal carcinoma cells. Knockdown of YBX1 inhibited migration and invasion in 5-8F cells, and over-expression of YBX1 promoted CNE1 cells migration and invasion. Transforming growth factor-ß1 (TGF-ß1) treatment led to epithelial-to-mesenchymal transition (EMT) in CNE1 cells accompanied by elevated YBX1 expression. On the contrary, knockdown of YBX1 partially inhibited the TGF-ß1-induced CNE1 cell migration, together with changes of EMT-associated markers. Our study revealed that TGF-ß1/YBX1 signaling might be one of novel mechanisms mediating EMT in NPC, providing a new target for the treatment of nasopharyngeal carcinoma.

Dual-energy CT virtual non-calcium: an accurate method for detection of knee osteoarthritis-related edema-like marrow signal intensity.

OBJECTIVES: To evaluate the performance of a dual-energy computed tomography (DECT) virtual non-calcium (VNCa) technique in the detection of edema-like marrow signal intensity (ELMSI) in patients with knee joint osteoarthritis (OA) compared to magnetic resonance imaging (MRI). METHODS: The study received local ethics board approval, and written informed consent was obtained. DECT and MRI were used to examine 28 knees in 24 patients with OA. VNCa images were generated by dual-energy subtraction of calcium. The knee joint was divided into 15 regions for ELMSI grading, performed independently by two musculoskeletal radiologists, with MRI as the reference standard. We also analyzed CT numbers through receiver operating characteristics and calculated cut-off values. RESULTS: For the qualitative analysis, we obtained CT sensitivity (Readers 1, 2 = 83.7%, 89.8%), specificity (Readers 1, 2 = 99.5%, 99.5%), positive predictive value (Readers 1, 2 = 95.3%, 95.7%), and negative predictive value (Readers 1, 2 = 97.9%, 98.7%) for ELMSI. The interobserver agreement was excellent (κ = 0.92). The area under the curve for Reader 1 and Reader 2 was 0.961 (95% CI 0.93, 0.99) and 0.992 (95% CI 0.98, 1.00), respectively. CT numbers obtained from the VNCa images were significantly different between regions with and without ELMSI (p < .001). CONCLUSIONS: VNCa images have good diagnostic performance for the qualitative and quantitative analysis of knee osteoarthritis-related ELMSI.

Prevalence and Risk Factors Associated With Physical and/or Sexual Abuse Among Female Middle School Students: A Cross- Sectional Study in Kinshasa, DRC.

This cross-sectional study sought to broaden the limited evidence on violence against young adolescent girls in non-conflict zones within the Democratic Republic of the Congo (DRC). Our goal was to estimate the prevalence of and the predictors of physical and/or sexual abuse among girls aged 11-18 years in Kinshasa. A total of 3,100 girls from five randomly selected schools were recruited by our team and given the questionnaires; among them, 3,011 (97.1%) participants completed the questionnaires and were included in the study for further analysis. After collecting all valid responses, the overall prevalence of physical and/or sexual abuse was sorted into the following categories: experienced physical abuse without a weapon (recorded by 70.1% of respondents), experienced physical abuse with a weapon (66.3% of respondents), attempted rape without penetration (76.5% of respondents), experienced attempted rape with penetration (73.9% of respondents), and experienced verbal sexual harassment (93.0%).Our logistic regression analysis indicated that specific kinds of living arrangements (such as only living with the father, mother, or a caregiver; odds ratio ranged 1.8 to 6.9) and places of residence (such as living in lower-class or middle-class districts; odds ratio ranged 1.7 to 6.2) had the strongest associations with higher risk pertaining to whether the respondent had experienced physical and/or sexual abuse in the past. Meanwhile, factors such as the students' level of education (both middle grade and upper grade) and occupation of the father (specifically whether holding a part-time job or retired) were deemed to be more protective. However, physical and/or sexual abuse prevalence was found to be high among middle school girls in Kinshasa. Therefore, we recommend that drastic policies and strategies aimed at socioeconomic issue and living condition ameliorations among families should be implemented to curtail physical and sexual abuse in the nonconflict zones of the DRC.

Novel homozygous protein-truncating mutation of BBS9 identified in a Chinese consanguineous family with Bardet-Biedl syndrome.

BACKGROUND: Bardet-Biedl syndrome (BBS) is a rare and genetically heterogeneous disease with a broad spectrum of clinical features, including but not limited to rod-cone dystrophy, postaxial polydactyly, central obesity, intellectual disability, hypogonadism, and renal dysfunction. Twenty-one BBS (Bardet-Biedl syndrome) genes have been identified to date. There is minimal mutation information on BBS in Chinese populations and the exact pathogenic mechanism of the null mutation of BBS9 remains unknown. METHODS: A patient from a Chinese consanguineous family presented with polydactyly, truncal obesity, intellectual disability, genital anomaly, and retinitis pigmentosa was analyzed in this study. Blood DNA and RNA were extracted from the blood of the proband and the parents. The proband was screened for mutations by whole-exome sequencing. The likely pathogenic mutation detected in the proband was further confirmed by the Sanger sequence in the family. Real-time RT-PCR was used to measure the expression of BBS9 in the proband and the control. RESULTS: Targeted exome sequencing identified a novel homozygous null mutation (NM_198428.3: c.445C>T) in the 6th exon of the BBS9 gene in the proband and Sanger sequencing was used to validate the heterozygosity in the parents. The mutation was validated to induce the nonsense-mediated decay of BBS9 messenger RNAs by real-time RT-PCR. CONCLUSIONS: The molecular findings helped to explain the clinical manifestations. The novel homozygous pathogenic variation expanded the mutational spectrum of the BBS9 gene in the Chinese population and will help to understand the pathogenic mechanism of BBS9 null mutation.

Awareness regarding and vaccines acceptability of human papillomavirus among parents of middle school students in Zunyi, Southwest China.

The objective of this study was to investigate the parent cognition of information regarding the human papillomavirus (HPV) and their willingness toward HPV vaccination of their middle-school-aged children in Zunyi, Guizhou Province, China.The results provide a basis for improving the awareness concerning HPV-related information as a key vaccination strategy for implementing the HPV vaccine in the local context. Methods include the random cluster sampling method and questionnaires to survey parents. General descriptive and single-factor analyses were used to assess cognition to determine factors influencing vaccine willingness. Of 1,074 parents, 28.2% (302) and 38.0% (408) had heard of HPV and its vaccine before the survey, and when given HPV-related information, 73.9% (794) parents were willing to vaccinate their children. Reasons why parents did or did not want the vaccination were surveyed, with lack of sufficient knowledge about HPV and its vaccine being the primary reason to refuse vaccination. Concerns about safety, effectiveness, and perceiving low risk are the biggest obstacle in promoting vaccination. When the price is <1000, most parents (56.1%) are willing to vaccinate their children; thus, cost is also one of the concerns. Therefore, strategies for improving public awareness regarding the risk of cervical cancer and confidence in vaccination must be considered by policymakers.If the national authority confirms that the vaccine is safe and effective, the vaccine should be included in the national immunization program to increase publicity, address safety concerns, and allow for price regulation.

Stainless steel corrosion via direct iron-to-microbe electron transfer by Geobacter species.

Microbial corrosion of iron-based materials is a substantial economic problem. A mechanistic understanding is required to develop mitigation strategies, but previous mechanistic studies have been limited to investigations with relatively pure Fe(0), which is not a common structural material. We report here that the mechanism for microbial corrosion of stainless steel, the metal of choice for many actual applications, can be significantly different from that for Fe(0). Although H2 is often an intermediary electron carrier between the metal and microbes during Fe(0) corrosion, we found that H2 is not abiotically produced from stainless steel, making this corrosion mechanism unlikely. Geobacter sulfurreducens and Geobacter metallireducens, electrotrophs that are known to directly accept electrons from other microbes or electrodes, extracted electrons from stainless steel via direct iron-to-microbe electron transfer. Genetic modification to prevent H2 consumption did not negatively impact on stainless steel corrosion. Corrosion was inhibited when genes for outer-surface cytochromes that are key electrical contacts were deleted. These results indicate that a common model of microbial Fe(0) corrosion by hydrogenase-positive microbes, in which H2 serves as an intermediary electron carrier between the metal surface and the microbe, may not apply to the microbial corrosion of stainless steel. However, direct iron-to-microbe electron transfer is a feasible route for stainless steel corrosion.

Adjustment Disorder in Female Breast Cancer Patients: Prevalence and Its Accessory Symptoms.

Women diagnosed with breast cancer may have serious psychological problems and will suffer from adjustment disorder (AjD). We investigated the prevalence of AjD in female breast cancer patients who were diagnosed within 1 year and examined the severe life events they experienced, and the most common symptoms of AjD. 342 newly diagnosed (<1 year) female breast cancer patients were recruited from Tongji Hospital and Hubei Cancer Hospital in Hubei, China, from July 2018 to May 2019. The patients completed the self-report questionnaire including demographic characteristics and the scale ADNM-20 for the diagnosis of AjD. SPSS20.0 was used for data analysis. As a result, the prevalence of AjD in breast cancer patients was 38.6%. Patients from rural areas and lacking of exercise were more likely to suffer from AjD (P<0.05). The prevalence of AjD in patients who did not regard breast cancer as the most severe life event was higher than that in patients who took breast cancer as the most severe life event (44.4% vs. 33.9%, P<0.05; OR=1.728, 95% CI=1.072-2.787). The symptom that scored highest was preoccupation (3.15). We found that the prevalence of AjD in women with breast cancer in this study is very high and warrants more attention. Patients from rural areas, lacking of exercise and subject to multiple stressors are more likely to suffer from AjD. The commonest and severe symptom is preoccupation.

[Application of stapled transanal rectum resection in the treatment of obstructed defecation syndrome].

OBJECTIVE: To evaluate the effectiveness and safety of stapled transanal rectum resection (STARR) in the treatment of obstructed defecation syndrome (ODS). METHODS: Fifty-six patients with ODS who had rectocele and/or intussusception were treated with STARR from January 2007 to August 2008. The incidence of preoperative and postoperative symptoms of ODS was compared. Symptomatic relief was also observed by using scoring system. RESULTS: The average operation time was 28 min, and in the first 3 days after operation the average VAS pain score was 3.2 points. Two patients experienced mild anal incontinence when followed-up to 6 months; 2 patients suffered mild anal pain during defecation due to slight anastomotic inflammation 2 and 4 months after the operation, respectively. No other complications was found. The mean follow-up period was 8 months after surgery, and the rate of symptoms of ODS reduced significantly compared with that before surgery, in particular the incidence of the difficult and obstructive defecation feelings decreased for more than 50 percent (P<0.05). Compared with that before the operation, the sense of no emptying stool decreased for 65 percent and all the other symptoms reduced for more than 72 percent (all P<0.05). CONCLUSION: The stapled transanal rectum resection is simple, less invasive, less painful and with fewer complications and more satisfactory recent effect in treating obstructed defecation syndrome.

Iron Corrosion via Direct Metal-Microbe Electron Transfer.

The concept that anaerobic microorganisms can directly accept electrons from Fe(0) has been controversial because direct metal-microbe electron transfer has previously only been indirectly inferred. Fe(0) oxidation was studied with Geobacter sulfurreducens strain ACL, an autotrophic strain that was previously shown to grow with electrons derived from a graphite cathode as the sole electron donor. Strain ACL grew with Fe(0) as the sole electron donor and fumarate as the electron acceptor. However, it appeared that at least a portion of the electron transfer was via H2 produced nonenzymatically from the oxidation of Fe(0) to Fe(II). H2, which accumulated in abiotic controls, was consumed during the growth of strain ACL, the cells were predominately planktonic, and genes for the uptake hydrogenase were highly expressed. Strain ACLHF was constructed to prevent growth on H2 or formate by deleting the genes for the uptake of hydrogenase and formate dehydrogenases from strain ACL. Strain ACLHF also grew with Fe(0) as the sole electron donor, but H2 accumulated in the culture, and cells heavily colonized Fe(0) surfaces with no visible planktonic growth. Transcriptomics suggested that the outer surface c-type cytochromes OmcS and OmcZ were important during growth of strain ACLHF on Fe(0). Strain ACLHF did not grow on Fe(0) if the gene for either of these cytochromes was deleted. The specific attachment of strain ACLHF to Fe(0), coupled with requirements for known extracellular electrical contacts, suggest that direct metal-microbe electron transfer is the most likely option for Fe(0) serving as an electron donor.IMPORTANCE The anaerobic corrosion of iron structures is expensive to repair and can be a safety and environmental concern. It has been known for over 100 years that the presence of anaerobic respiratory microorganisms can accelerate iron corrosion. Multiple studies have suggested that there are sulfate reducers, methanogens, and acetogens that can directly accept electrons from Fe(0) to support sulfate or carbon dioxide reduction. However, all of the strains studied can also use H2 as an electron donor for growth, which is known to be abiotically produced from Fe(0). Furthermore, no proteins definitely shown to function as extracellular electrical contacts with Fe(0) were identified. The studies described here demonstrate that direct electron transfer from Fe(0) can support anaerobic respiration. They also map out a simple genetic approach to the study of iron corrosion mechanisms in other microorganisms. A better understanding of how microorganisms promote iron corrosion is expected to lead to the development of strategies that can help reduce adverse impacts from this process.

[Adsorption, Reclaim, and Regeneration of Cd by Magnetic Calcium Dihydrogen Phosphate Nanoparticles].

In order to improve the adsorption-separation of Cd2+ in water treatment, magnetic Fe3O4 coated Ca(H2PO4)2 nanoparticles (NMCDP) were developed by coprecipitation. The properties of these nanoparticles were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and magnetization curves. Experiments were carried out to investigate the effect of adsorption, reclaiming, and regeneration. The results showed that NMCDP was a stable material with a particle size of 60 nm and a saturation magnetization of 30.9 emu·g-1. The adsorption rate of Cd2+ by NMCDP was fast, and adsorption equilibrium could be achieved within 1 hour. The kinetic data were well fitted by a pseudo-second-order model, and the isotherm adsorption data agreed with the Langmuir and Freundlich model, with a maximum adsorption capacity of 142.50 mg·g-1. The adsorption capacity of Cd2+ was affected by the pH and increased when the pH was increased from 2 to 3, while with continued increase of the pH of the solution, the adsorption capacity gradually became stable. The coexisting ions in the solution had an effect on the adsorption of Cd2+, especially the divalent cation Cu2+. The NMCDP could be regenerated by using 0.01 mol·L-1 HCl and EDTA-Na2, and the results indicated that it could be recycled with a desorption rate of 68% by EDTA-Na2 solution.

A Membrane-Bound Cytochrome Enables Methanosarcina acetivorans To Conserve Energy from Extracellular Electron Transfer.

Extracellular electron exchange in Methanosarcina species and closely related Archaea plays an important role in the global carbon cycle and enhances the speed and stability of anaerobic digestion by facilitating efficient syntrophic interactions. Here, we grew Methanosarcina acetivorans with methanol provided as the electron donor and the humic analogue, anthraquione-2,6-disulfonate (AQDS), provided as the electron acceptor when methane production was inhibited with bromoethanesulfonate. AQDS was reduced with simultaneous methane production in the absence of bromoethanesulfonate. Transcriptomics revealed that expression of the gene for the transmembrane, multiheme, c-type cytochrome MmcA was higher in AQDS-respiring cells than in cells performing methylotrophic methanogenesis. A strain in which the gene for MmcA was deleted failed to grow via AQDS reduction but grew with the conversion of methanol or acetate to methane, suggesting that MmcA has a specialized role as a conduit for extracellular electron transfer. Enhanced expression of genes for methanol conversion to methyl-coenzyme M and the Rnf complex suggested that methanol is oxidized to carbon dioxide in AQDS-respiring cells through a pathway that is similar to methyl-coenzyme M oxidation in methanogenic cells. However, during AQDS respiration the Rnf complex and reduced methanophenazine probably transfer electrons to MmcA, which functions as the terminal reductase for AQDS reduction. Extracellular electron transfer may enable the survival of methanogens in dynamic environments in which oxidized humic substances and Fe(III) oxides are intermittently available. The availability of tools for genetic manipulation of M. acetivorans makes it an excellent model microbe for evaluating c-type cytochrome-dependent extracellular electron transfer in ArchaeaIMPORTANCE The discovery of a methanogen that can conserve energy to support growth solely from the oxidation of organic carbon coupled to the reduction of an extracellular electron acceptor expands the possible environments in which methanogens might thrive. The potential importance of c-type cytochromes for extracellular electron transfer to syntrophic bacterial partners and/or Fe(III) minerals in some Archaea was previously proposed, but these studies with Methanosarcina acetivorans provide the first genetic evidence for cytochrome-based extracellular electron transfer in Archaea The results suggest parallels with Gram-negative bacteria, such as Shewanella and Geobacter species, in which multiheme outer-surface c-type cytochromes are an essential component for electrical communication with the extracellular environment. M. acetivorans offers an unprecedented opportunity to study mechanisms for energy conservation from the anaerobic oxidation of one-carbon organic compounds coupled to extracellular electron transfer in Archaea with implications not only for methanogens but possibly also for Archaea that anaerobically oxidize methane.

[Temporal and spatial change of climate resources and meteorological disasters under climate change during winter crop growing season in Guangdong Province, China.] / 气候变暖背景下广东冬种生产季气候资源和气象灾害的时空变化.

Trend analysis method was applied to analyze the general variation characteristics of the climate resources and meteorological disasters of growing season of the winter planting in Guangdong before (1961-1996) and after climate warming (1997-2015). Percentile method was employed to determine thresholds for extreme cold and drought in major planting regions, and the characteristics of extreme disasters since climate warming were analyzed. The results showed that, by comparing 1997-2015 with 1961-1996, the heat value in winter growing season increased significantly. The belt with a higher heat value, where the average temperature was ≥15 ℃ and accumulated temperature was ≥2200 ℃·d, covered the main winter production regions as Shaoguan, Zhanjiang, Maoming, Huizhou, Meizhou and Guangzhou. Meanwhile, the precipitation witnessed a slight increase. The regions with precipitations of 250-350 mm included Zhanjiang, Maoming, Huizhou, Guangzhou and Meizhou. Chilling injury in the winter planting season in the regions decreased, the belt with an accumulated chilling of <2 ℃·d covered the major geographic parts of the involved regions as Zhanjiang, Maoming, Guangzhou and Huizhou; and the belt with an accumulated chilling of 8-16 ℃·d covered the major geographic parts of Shaoguan and Meizhou. Meanwhile, the drought days decreased, the belt with drought days ≥50 included the major geographic parts of Zhanjiang, Maoming, Huizhou, Guangzhou and the belt with drought days <50 included the major geographic parts of Shaoguan. The typical case of the extreme disasters showed that the extreme chilling injury and drought in the main producing regions should not be overlooked. Maoming, Huizhou and Meizhou were at higher risk of extreme chilling injury, followed by Shaoguan and Guangzhou. Zhanjiang and Maoming faced the highest risk of extreme drought, Huizhou and Guangzhou took the second place, Shaoguan and Meizhou went last. During 1997-2015, the heat of winter season increased significantly, the trend of chilling and drought decreased, however, the extreme disasters occurred frequently and the risks were higher in winter production areas. It was suggested that the winter planting should be closely integrated with climate resources and the occurrence law of meteorological disasters in growing season.

Hypoglycemic activity and acute oral toxicity of chromium methionine complexes in mice.

The hypoglycemic activity of chromium methionine (CrMet) in alloxan-induced diabetic (AID) mice was investigated and compared with those of chromium trichloride hexahydrate (CrCl3·6H2O) and chromium nicotinate (CrNic) through a 15-day feeding experiment. The acute oral toxicity of CrMet was also investigated in ICR (Institute for Cancer Research) mice by a single oral gavage. The anti-diabetic activity of CrMet was explored in detail from the aspects of body weight (BW), blood glucose, triglyceride, total cholesterol, liver glycogen levels, aspartate transaminase (AST) and alanine transaminase (ALT) levels. The obtained results showed that CrMet had beneficial effects on glucose and lipid metabolism, and might possess hepatoprotective efficacy for diabetes. Daily treatment with 500 and 1000µg Cr/kg BW of CrMet in AID mice for 15 days indicated that this low-molecular-weight organic chromium complex had better bioavailability and more beneficial effects on diabetics than CrCl3·6H2O. CrMet also had advantage over CrNic in the control of AST and ALT activities. Acute toxicity studies revealed that CrMet had low toxicity potential and relatively high safety margins in mice with the LD50 value higher than 10.0g/kg BW. These findings suggest that CrMet might be of potential value in the therapy and protection of diabetes.

Theoretical investigation of optical and paramagnetic resonance spectra of [NiF6](4-) clusters with orthorhombic symmetry.

The ground state absorption spectra of [NiF6](4-) clusters with orthorhombic symmetry (Ni(2+) in NiF2 crystal and Ni(2+)-doped ZnF2 crystal, D2h point group) are theoretically calculated and assigned by diagonalization of 45×45 complete energy matrix for 3d(8) configuration and the spin-Hamiltonian (SH) parameters (zero-field splitting D and E, and g factors gx, gy, gz) are studied by use of high-order perturbation method, in the frame of semi-empirical molecular orbital (MO) scheme based on strong crystal field framework. In those energy matrix, all the configuration interactions though the cubic crystal field (CF), the orthorhombic crystal field, the Coulomb interaction are taken into account. The calculated results are in good agreement with the experimental data. The local structure (bond length and bond angle) of [NiF6](4-) clusters are determined, and the results shows that the structure data given by Stout are more plausible than those given by Baur.

Theoretical investigations of optical spectra and electron paramagnetic resonance spectra of LiCl:Ni²âº crystals.

The complete energy matrices (45 × 45) including low symmetry ligand field (C(4v)) and Coulomb interactions for 3d(8) ions have been constructed, and the high-order perturbation formulas of spin-Hamiltonian (SH) parameters g factors g(//), g(⊥) and zero-field splitting (ZFS) parameter D for ground state (3)A(2g) of the 3d(8) ions in the tetragonal symmetry environment have been derived. In those formulas both the crystal field (CF) mechanism and the charge transfer (CT) mechanism are taken into account. The complete energy matrices and the high-order perturbation formulas are applied to calculate the energy levels and SH parameters of the Ni(2+) ion in LiCl crystal respectively. The results are in reasonable agreement with the experimental data and indicate that CT mechanism plays important role in the understanding of SH parameters, especially the g factors. All the multiplet energy are assigned theoretically and the local structures of LiCl:Ni(2+) are established.

[Complications after procedure for prolapse and hemorrhoids for circular hemorrhoids].

OBJECTIVE: To investigate the perioperative and postoperative long-term complications of procedure for prolapse and hemorrhoids(PPH) for the treatment of circular internal hemorrhoids and circular mixed hemorrhoids. METHODS: A retrospective study was performed in 2152 patients with circular internal hemorrhoids and circular mixed hemorrhoids eligible for PPH from January 2002 to December 2011. The perioperative and postoperative long-term complications were recorded and assessed. RESULTS: The median length of follow-up was 73 months. Perioperative complications and adverse events were reported including acute urinary retention(n=360, 16.7%) which was managed by temporary cathether indwelling, anastomotic bleeding(n=45, 2.1%) managed by surgical or endoscopic procedures, chronic anoperineal sustained pain(n=30, 1.4%) managed by local treatment or stapler removal, and thrombosed external hemorrhoid(n=28, 1.2%) managed by conservative treatment or resection. Long-term postoperative complications were reported including mild fecal incontinence(n=112, 6.3%), postoperative recurrence(n=82, 4.6%), anal distention and defecatory urgency(n=50, 2.8%), anastomotic stenosis(n=4, 0.2%). Postoperative recurrence developed in 82 patients(4.6%), 28 of whom were managed by repeat PPH and 54 by conservative treatment. CONCLUSION: PPH appears to be a safe technique for patients with circular internal hemorrhoids and circular mixed hemorrhoids.