[Characteristics and drivers of vegetation temporal dynamics in Hunan Province of China during 2002-2020]. / 湖南省2002­2020å¹´æ¤è¢«åŠ¨æ€æ¼”å˜ç‰¹å¾åŠå½±å“å› å­.

Understanding the influences of climate change and human activities on vegetation change is the foundation for effective ecosystem management. Based on the 250 m MODIS-NDVI data from 2002 to 2020, we employed Theil-Sen Median trend analysis and the Mann-Kendall test to quantify vegetation change in Hunan Province. By combining with meteorological, nighttime light index, land cover and other data, residual analysis and correlation analysis, we examined the impacts of human activities and climate change on vegetation dynamics at both the pixel level and the county level. The results showed that the normalized difference vegetation index (NDVI) in Hunan Province exhibited a spatial pattern of "overall improvement with localized degradation" during 2002-2020. Approximately 64.9% of the study area experienced significant vegetation improvement, mainly occurring in the western and central-southern parts of Hunan Province. 1.4% of the study area experienced significant vegetation degradation, mostly in the newly developed urban areas and the farmland in the Dongting Lake Plain. Human activities and climate change jointly promoted vegetation improvement in 67.9% of the study area. Human activities and climate contributed to 96% and 4% of the NDVI change, respectively. At the county level, human activities contributed to over 80% of the NDVI change in each district or county. The impacts of human activities on vegetation change exhibited significant spatial heterogeneity. Urban expansion led to vegetation degradation in the newly developed areas, while vegetation growth appeared in the old developed urban areas. The ecological restoration projects promoted vegetation restoration in the western part of Hunan Province. This study could help us better understand the spatiotemporal variations of vegetation and their responses to climate change and human activities, which would offer scientific basis for effective ecological restoration policy.

An inhibitor/anti-inhibitor system controls the activity of lytic transglycosylase MltF in Pseudomonas aeruginosa.

IMPORTANCE: A peptidoglycan cell wall is an essential component of almost all bacterial cell envelopes, which determines cell shape and prevents osmotic rupture. Antibiotics that interfere with peptidoglycan synthesis have been one of the most important treatments for bacterial infections. Peptidoglycan must also be hydrolyzed to incorporate new material for cell growth and division and to help accommodate important envelope-spanning systems. However, the enzymes that hydrolyze peptidoglycan must be carefully controlled to prevent autolysis. Exactly how this control is achieved is poorly understood in most cases but is a highly active area of current research. Identifying hydrolase control mechanisms has the potential to provide new targets for therapeutic intervention. The work here reports the important discovery of a novel inhibitor/anti-inhibitor system that controls the activity of a cell wall hydrolase in the human pathogen Pseudomonas aeruginosa, which also affects resistance to an antibiotic used in the clinic.

Endoscopic retrograde appendicitis therapy (ERAT) vs appendectomy for acute uncomplicated appendicitis: A prospective multicenter randomized clinical trial.

OBJECTIVE: To compare the efficacy and feasibility of endoscopic retrograde appendicitis therapy (ERAT) with appendectomy for treating acute uncomplicated appendicitis. METHODS: This was a prospective multicenter randomized trial in which consecutive patients were randomized at a ratio of 1:1 to receive either ERAT or appendectomy. The outcomes included technical success rate, procedure time, postoperative pain relief, postoperative analgesic use, time to soft diet intake, length of postoperative hospital stay, postoperative complications, and recurrence rate. RESULTS: From August 2013 to December 2015, 110 patients with acute uncomplicated appendicitis were randomized to ERAT or appendectomy. The technical success rate was 94.55% for ERAT compared with 100% for appendectomy. Recurrence of appendicitis within 3-year follow-up occurred in 8 patients following ERAT. Postoperative abdominal pain was less frequent with ERAT than with appendectomy (21.15% [11/52] vs 87.27% [48/55], P < 0.001). Soft diet intake begun earlier after ERAT than appendectomy (6 h vs 48 h, P < 0.001), and post-procedure hospital stay was shorter (3 days vs 5 days, P < 0.001), as was the use of analgesics postoperatively (9.09% vs 49.09%, P < 0.001). CONCLUSIONS: ERAT is a feasible, safe, and effective alternative approach for the management of acute uncomplicated appendicitis. Compared with appendectomy, advantages of ERAT include no skin wound, organ preservation, reduced postoperative pain, early food intake, quick recovery, fewer postoperative complications, and shorter post-procedure hospitalization. The unsolved problem related to ERAT is the recurrence of appendicitis.

An Inducible Nitric Oxide Synthase Dimerization Inhibitor Prevents the Progression of Osteoarthritis.

Objective: Osteoarthritis (OA) is a degenerative joint disease. Excessive nitric oxide (NO) mediates the chondrocyte inflammatory response, apoptosis, and extracellular matrix (ECM) degradation during the occurrence and development of OA. NO in chondrocytes is mainly produced by inducible nitric oxide synthase (iNOS). The aim of this study was to design and synthesize an iNOS dimerization inhibitor and evaluate its effects on chondrocyte inflammation and articular cartilage injury in OA via in vitro and in vivo experiments. Design: The title compound 22o was designed, synthesized, and screened based on a previous study. The effects of different concentrations (5, 10, and 20 µM) of compound 22o on chondrocyte inflammatory response and ECM anabolism or catabolism were evaluated by Western blot and real-time quantitative reverse transcription-polymerase chain reaction using the rat chondrocyte model of IL-1ß-induced OA. Furthermore, different doses (40 and 80 mg/kg) of compound 22o were administered by gavage to a rat OA model induced by anterior cruciate ligament transection (ACLT), and their protective effects on the articular cartilage were evaluated by histopathology and immunohistochemistry. Results: Compound 22o showed effective iNOS inhibitory activity by inhibiting the dimerization of iNOS. It inhibited the IL-1ß-induced expression of cyclooxygenase-2 (COX-2) and matrix metalloproteinase 3 (MMP3) in the chondrocytes, decreased NO production, and significantly increased the expression levels of the ECM anabolic markers, aggrecan (ACAN), and collagen type II (COL2A1). Gavage with compound 22o was found to be effective in the rat OA model induced by ACLT, wherein it regulated the anabolism and catabolism and exerted a protective effect on the articular cartilage. Conclusions: Compound 22o inhibited the inflammatory response and catabolism of the chondrocytes and reduced articular cartilage injury in the rat OA model, indicating its potential as a disease-modifying OA drug.

[Application value of imaging examination in the diagnosis of Muller-Weiss disease].

OBJECTIVE: To analyze radiological characteristics of Muller-Weiss disease, evaluate the clinical value of the imaging examination in diagnosis of Muller-Weiss disease. METHODS: The imaging data of 26 patients with Muller-Weiss disease were collected from September 2015 to August 2020, including 7 males and 19 females, aged 43 to 68 years old with an average of (52.7±4.6) years old. In the X-ray examination observed the shape and position of the navicular bone. The talar-first metatarsal angle(TFM) was measured on the weight-bearing anteroposterior radiograph. The arch angle and angle between mid-axis of talus and mid-axis of the first metatarsal(Meary angle) were measured on the weight-bearing lateral radiographs. The morphology, density, adjacent joint space and position of the navicular bone were evaluated by computed tomography(CT), and magnetic resonance imaging(MRI) was used to observe the shape, signal, cartilage and surrounding soft tissue changes of the navicular bone. RESULTS: Among 26 patients, 21 cases were unilateral and 5 cases were bilateral;X-ray examination showed that the lateral part of navicular bone of foot was compressed and flattened, showing"comma like"or"drop like", navicular moved to the medial side, partial fragmentation of bone, peripheral articular hyperplasia, uneven density and narrowing of relationship gap. According to Meary angle and deformity degree of the affected foot on the lateral X-ray of the load-bearing foot, Maceira staging was performed. There were 0 cases in stageⅠ, 2 cases in stage Ⅱ, 11 cases in stage Ⅲ, 9 cases in stage Ⅳand 4 cases in stage Ⅴ. CT examination showed bone fragmentation, medial displacement of navicular bone and formation of the talocalcaneal joint. MRI examination showed the irregular shape and uneven signal of navicular bone, narrowing of joint space, talocalcaneal joint surface hyperplasia and cartilage destruction, tarsal joint effusion and swelling of surrounding soft tissue. CONCLUSION: Muller-Weiss disease has specific imaging manifestation, and an accurate diagnosis can be made based on the patient's age, gender, and clinincal history. Preoperative imaging examination can stage the disease, help clinicians to formulate better surgical plans, and postoperative imaging examination can better evaluate the surgical effect.

[Prevalence of and associated factors for prostate calcification in ≥40-year-old males with benign prostatic enlargement].

OBJECTIVE: To investigate the prevalence of and risk factors for prostate calcification (PCal) in ≥40 years old males with benign prostatic enlargement (BPE) found in health checkup. METHODS: We retrospectively analyzed the data on 671 ≥40-year-old men found with BPE in health checkup and investigated the prevalence of and risk factors for PCal in BPE males aged ≥40 years by univariate and multivariate analyses. RESULTS: Among 1 582 men aged ≥40 years undergoing health checkup, 671 were found with BPE and 274 (17.3%) with both BPE and PCal. The incidence rate of PCal was 40.8% (274/671) in the BPE patients, which was increased with age (trend χ2 = 5.289, P = 0.021), with statistically significant differences in different age groups (χ2 = 9.243, P = 0.026). Significant differences were also observed in age, height, estimated glomerular filtration rate (eGFR), urine pH level and the number of cases of uneven prostatic echoes between the BPE patients with and those without PCal (P < 0.05). Logistic regression analysis showed that age (OR = 1.027, 95% CI: 1.010－1.044), urine pH (OR = 1.446, 95% CI: 1.148－1.823) and uneven prostatic echoes (OR = 2.150, 95% CI: 1.108－4.174) were the associated factors for PCal in BPE patients aged ≥40 years. CONCLUSION: The incidence rate of PCal is high and increased with age in BPE patients aged ≥40 years, and age, urine pH and uneven prostatic echoes are associated factors for PCal in this cohort.

Is polycystic ovary syndrome appropriately diagnosed by obstetricians and gynaecologists across China: a nationwide survey.

BACKGROUND: To describe the diagnostic criteria used and their application accuracy in the practice of polycystic ovary syndrome (PCOS) caring among obstetricians and gynaecologists across China. METHODS: This was an Online cross-sectional survey of Obstetricians and gynecologists involved in PCOS caring conducted via the largest continuing education platform of obstetrics and gynecology across China from September 2019 to November 2019. RESULTS: A total of 2,328 respondents were eligible for the final analysis. Of these, 94.5 % were general obstetricians and gynaecologists (Ge-ObGyn), and 5.5 % were reproductive endocrinologists (Re-ObGyn). Overall, the most frequently used criteria were the Androgen Excess and Polycystic Ovary Syndrome Society (AE-PCOS) criteria (48.2 %), followed by the Rotterdam criteria (35.7 %) and NIH criteria (12.1 %). Of the respondents, 31.3 % used their diagnostic criteria in their clinical practice. More respondents who chose the Rotterdam criteria could accurately apply the diagnostic criteria than those who chose the AE-PCOS criteria (41.2 % vs. 32.1 %, P < 0.001). Compared with Ge-ObGyn, Re-ObGyn were less likely to use the AE-PCOS criteria (adjusted odds ratio, 0.513; 95 % CI, 0.328-0.802; P < 0.05) and 1.492 times more likely to accurately use their criteria (95 % CI, 1.014-2.196; P < 0.05). CONCLUSIONS: Less than one-third of obstetricians and gynaecologists across China could accurately use the diagnostic criteria they choose to diagnose PCOS. There is an urgent need to train obstetricians and gynaecologists on PCOS diagnosis in an effort to improve the medical care quality of patients with PCOS.

Simultaneous quantitation of cytokinin bases and their glycoconjugates with stable isotope labelling ultrahigh performance liquid chromatography mass spectrometry.

Cytokinins (CKs) are one class of important phytohormones widely investigated in most aspects of plant life. Similar to other phytohormones, CKs and their glycoconjugates are hydrophilic. Their ionization efficiencies for mass spectrometry (MS) detection are rather poor, whereas their retention and separation on reverse phase liquid chromatography (RPLC) are often unsatisfying. Chemical isotope labelling LC-MS analysis methods have been developed for most other phytohormones, enhancing their LC separations and quantitative sensitivity. However, there are currently no reports for chemical-labelled CKs. Here, we report a new chemical isotope labelling LC-MS analytical method for one-pot derivatization of CK bases and their glycoconjugates, based on differential benzylation labelling of the adenine skeleton of CKs with benzyl bromide and its deuterium isotope-labelled reagent. Benzylation alters the hydrophilicity of CKs and their glycoconjugates, improving their retention and separation on RPLC. The developed method demonstrated enhanced sensitivity, as the CKs and their glycoconjugates could be analysed with LODs within the range of 0.62-25.9 pg/mL. The method also demonstrated good intra- and inter-day precisions with standard deviations in the range of 1.9%-13.0%, and acceptable accuracy with recoveries in the range of 84.0%-119.9%. The developed method was employed on the quantitation of CKs in the fresh roots of Astragalus membranaceus collected from both fertilized and unfertilized fields. The significant impact that fertilizers had on endogenous CKs metabolism was observed. As such, monitoring endogenous CKs and their metabolites might be promising to control fertilizer abuse.

[Causes of and risk factors for failure in catheter removal after transurethral resection of the prostate].

OBJECTIVE: To find the causes of the failure in the first catheter removal (CR) after transurethral resection of the prostate (TURP) and the related risk factors. METHODS: We collected the clinical data on 285 BPH patients treated by TURP from June 2015 to May 2018. We divided the cases into a successful CR (SCR) and a failed CR (FCR) group and investigated the risk factors for the first CR after TURP by multivariate logistic regression analysis. RESULTS: CR was successfully performed in 246 and failed in 39 of the 285 cases. In the FCR group, post-CR urinary retention occurred in 15 cases immediately after, severe urinary tract irritation in 13, massive gross hematuria in 7 and urinary incontinence in 4 within 1 month. Multivariate logistic regression analysis showed that the independent risk factors for CR failure included IPSS (OR = 5.106, P = 0.013), preoperative urinary tract infection (OR = 3.835, P = 0.041), prostate volume (OR = 4.160, P = 0.011) and catheter compression time (OR = 4.051, P = 0.017). CONCLUSIONS: The common causes of the failure in catheter removal after TURP included early postoperative urinary retention, urinary infection, secondary hematuria and urinary incontinence.

Human Umbilical Cord Wharton's Jelly Derived Mesenchymal Stromal Cells May Attenuate Sarcopenia in Aged Mice Induced by Hindlimb Suspension.

BACKGROUND Since the use of human umbilical cord Wharton's Jelly derived mesenchymal stromal cells (hWJ-MSCs) to treat sarcopenia has not been explored, we studied the effects of hWJ-MSCs in aged male C57BL/6J mice with sarcopenia induced by hindlimb suspension, and explored the potential mechanism. MATERIAL AND METHODS Hindlimb suspension was used to induce sarcopenia in 24-month-old C57BL/6J mice and green fluorescent protein-tagged hWJ-MSCs and controls were transplanted into mice via tail vein or local intramuscular injection. After hWJ-MSC transplantation, changes in whole body muscle strength and endurance, gastrocnemius muscle weight and myofiber cross-sectional area (CSA) were studied. Proliferation of skeletal muscle stem cell, apoptosis, and chronic inflammation were also investigated. RESULTS We demonstrated that whole body muscle strength and endurance, gastrocnemius muscle mass, and CSA were significantly increased in hWJ-MSC-transplanted mice than in controls (P<0.05). In hWJ-MSC-transplanted mice, apoptotic myonuclei was reduced, and BrdU and Pax-7 expression indices of gastrocnemius muscles were increased (P<0.05). Tumor necrosis factor (TNF)-α and interleukin (IL)-6 were downregulated, and IL-4 and IL-10 were upregulated (P<0.05). CONCLUSIONS hWJ-MSCs may ameliorate sarcopenia in aged male C57BL/6J mice induced by hindlimb suspension, and this may be via activation of resident skeletal muscle satellite cells, reduction of apoptosis, and less chronic inflammation.

Combination Therapy with LXW7 and Ceria Nanoparticles Protects against Acute Cerebral Ischemia/Reperfusion Injury in Rats.

Ischemia/reperfusion is known to greatly increase oxidative stress in the penumbra, which results in brain damage. Integrin αvß3 is selectively up-regulated with ischemic injury to the brain and remains elevated throughout reperfusion. We determined whether or not a new compound biotinylated-LXW7-ceria nanoparticle (CeNP) (bLXW7-CeNP) plays a role in brain protection in the rat model of middle cerebral artery occlusion/reperfusion and shows better effects than CeNPs alone in improving the outcomes of focal oxidative stress and apoptosis more effectively. Male Sprague-Dawley rats were subjected to focal cerebral ischemia for 2 h followed by a 24-h reperfusion. Drug treatment was intravenously administered via the caudal vein 1 h after occlusion. Rats were randomly divided into the following 4 groups: bLXW7-CeNP treatment group (0.5 mg/kg); CeNP treatment group (0.5 mg/kg); control saline group; and sham group. Brains were harvested 24 h after reperfusion, and the neurologic deficit scores, infarction volume, blood-brain barrier (BBB) disruption, and the level of oxidative stress and apoptosis were determined. Results showed that the bLXW7-CeNP and CeNP treatments could improve neurologic deficit scores, infarction volume, BBB disruption, and the level of oxidative stress and apoptosis. Compound bLXW7-CeNP treatment exhibited better effects than CeNp treatment and showed remarkable statistical differences in the infarction volume, the degree of BBB breakdown, the apoptosis and oxidative stress, apart from neurologic deficit scores. Thus, we concluded that bLXW7-CeNP protects against acute cerebral ischemia/reperfusion injury. BLXW7, as a ligand of integrin αvß3, may be able to effectively localize the anti-oxidant CeNPs to the ischemic penumbra region, which may provide more adequate opportunities for CeNPs to exert anti-oxidative stress effects and subsequently reduce apoptosis in acute cerebral ischemia/reperfusion.

[Survey of prevention knowledge and behavior of echinococcosis and influencing factors in residents in agricultural and pastoral areas of Maerkang City].

OBJECTIVE: To master the prevention knowledge and behavior of echinococcosis and the influencing factors in residents in agricultural and pastoral areas of Maerkang City, so as to provide the reference for formulating the policy and strategy of echinococcosis prevention and control. METHODS: In April, 2017, 796 residents in agricultural and pastoral areas of Maerkang City were selected by the multi-stage stratified random sampling method, and surveyed with questionnaires. The main questions included the prevention knowledge and related behaviors of echinococcosis. RESULTS: The awareness rate of prevention knowledge of echinococcosis was 70.1% (558/796). The awareness rate was the lowest in the group aged 15 to 25 years. The difference of knowledge awareness rate was statistically significant among the different age groups (χ2 = 16.408, P < 0.01). The knowledge awareness rate of the people with middle school or above educational level was higher than that of the people with primary school or below educational level (χ2 = 4.869, P = 0.027). The knowledge awareness rate of the dog owners was lower than that of the people without a dog (χ2 = 11.384, P = 0.001). The knowledge awareness rate in the people who received the knowledge training of three times or more was higher than that in the people who received the knowledge training of two times or less (χ2 = 11.439, P = 0.003). The logistic regression showed that the age, educational level, training times and dog raising were the main influencing factors. The related behavior survey showed that 32.7% (260/796) of residents did not drink unboiled water, 37.0% (61/165) of dog owners tied the dog, 43.6% (72/165) of dog owners fed the dogs with anthelmintic regularly, and only 10.3% (17/165) of dog owners buried the dog's dung. CONCLUSIONS: The awareness rate of echinococcosis prevention knowledge in Maerkang City should be improved. The health education should be focused on the young people, people with low educational level, and people who have dogs. The behaviors of drinking unboiled water, tying dogs, feeding dogs with anthelmintic regularly, and burying dog' s dung should be advocated.

Quantum anomalous Hall effect and topological phase transition in two-dimensional antiferromagnetic Chern insulator NiOsCl6.

By doing calculations based on density functional theory, we predict that the two-dimensional anti-ferromagnetic (AFM) NiOsCl6 as a Chern insulator can realize the quantum anomalous Hall (QAH) effect. We investigate the magnetocrystalline anisotropy energies in different magnetic configurations and the Néel AFM configuration is proved to be ground state. When considering spin-orbit coupling (SOC), this layered material with spins perpendicular to the plane shows properties as a Chern insulator characterized by an inversion band structure and a nonzero Chern number. The nontrivial band gap is 37 meV and the Chern number C = -1, which are induced by a strong SOC and AFM order. With strong SOC, the NiOsCl6 system performs a continuous topological phase transition from the Chern insulator to the trivial insulator upon the increasing Coulomb repulsion U. The critical U c is indicated as 0.23 eV, at which the system is in a metallic phase with [Formula: see text]. Upon increasing U, the E g reduces linearly with C = -1 for 0 < U < U c and increases linearly with C = 0 for U > U c . At last we analysis the QAH properties and this continuous topological phase transition theoretically in a two-band [Formula: see text] model. This AFM Chern insulator NiOsCl6 proposes not only a promising way to realize the QAH effect, but also a new material to study the continuous topological phase transition.

Long non-coding RNA ANRIL in gene regulation and its duality in atherosclerosis.

The antisense transcript long non-coding RNA (lncRNA) (antisense non-coding RNA in the INK4 locus, ANRIL) is an antisense of the cyclin-dependent kinase inhibitor 2B (CDKN2B) gene on chromosome 9p21 that contains an overlapping 299-bp region and shares a bidirectional promoter with alternate open reading frame (ARF). In the context of gene regulation, ANRIL is responsible for directly recruiting polycomb group (PcG) proteins, including polycomb repressive complex-1 (PRC-1) and polycomb repressive complex-2 (PRC-2), to modify the epigenetic chromatin state and subsequently inhibit gene expression in cis-regulation. On the other hand, previous reports have indicated that ANRIL is capable of binding to a specific site or sequence, including the Alu element, E2F transcription factor 1 (E2F1), and CCCTC-binding factor (CTCF), to achieve trans-regulation functions. In addition to its function in cell proliferation, adhesion and apoptosis, ANRIL is very closely associated with atherosclerosis- related diseases. The different transcripts and the SNPs that are related to atherosclerotic vascular diseases (ASVD-SNPs) are inextricably linked to the development and progression of atherosclerosis. Linear transcripts have been shown to be a risk factor for atherosclerosis, whereas circular transcripts are protective against atherosclerosis. Furthermore, ANRIL also acts as a component of the inflammatory pathway involved in the regulation of inflammation, which is considered to be one of the causes of atherosclerosis. Collectively, ANRIL plays an important role in the formation of atherosclerosis, and the artificial modification of ANRIL transcripts should be considered following the development of this disease.

[Characteristics of nitrogen and phosphorus removal and control of membrane fouling in MBR and SMBR].

To improve the efficiency and running stability of wastewater advanced treatment, a sequencing membrane bioreactor (SMBR) and a traditional membrane bioreactor (MBR) were used to investigate the characteristics of nitrogen and phosphorus removal, and the effect of anoxic time on treatment systems and membrane fouling. Simultaneously, molecular biology techniques were applied to analyze the composition of microbial community and the structure of suspended sludge. The results showed that SMBR had higher efficiency in removing TN than MBR, which indicated that intermittent aeration could enhance the ability of nitrogen removal. SMBR and MBR had a similar removal efficiency of NH4(+)-N, TP, COD, and turbidity with the removal rates of 94%, 78%, 80%, and 97%, respectively. Extension of SMBR anoxic time had no effect on COD, NH4(+) -N removal but decreased TN and TP removal rate, dropping from 61% and 74% to 46% and 52%, respectively. Intermittent aeration and powder activated carbon (PAC) could both mitigate membrane fouling. The analysis on microbial community indicated that there was no difference in the composition and structure of microbial community between SMBR and MBR. Nitrospira and Dechloromonas were both highly abundant functional groups, which provided the basis for highly efficient control of bioreactors.

[Trend in acid deposition at Tieshanping, Chonging during 2001-2010].

Although the total emission of sulphure dioxide (SO2) was reduced by more than 10% in the Eleventh Five-Year-Plan (2006-2010) in China, the total emission of nitrogen oxides (NOx) in the same period kept increasing. In order to evaluate the effects of the emission changes on acid depostion, a ten-year monitoring on forest throughfall was carried out from 2001 to 2010 at Tieshanping, Chongqing in Southwestern China. The results indicated there was a significantly decreasing trend of sulphur deposition and an increasing trend of nitrogen deposition, which coincided well with the dicreasing trend of SO2 emission and increasing tread of NOx emission in Chongqing, respectively. As the net effect, acid deposition was reduced by the emission contol. However, the total deposition of sulphur and nitrogen in 2010 was estimated to be 9.9 keq x (hm2 x a)(-1) and 4.5 keq x (hm2 x a)(-1), respectively according to the throughfall data, with the former probably overestimated by 28% and the latter underestimated by 50%. Since both the sulphur deposition and nitrogen deposition are higher than the highest levels in the history in Europe and North America, acid deposition is still a serious issue in Chongqing.

Implantation of hydroxyapatite-titanium corneal implants in rat cornea.

PURPOSE: To evaluate the biocompatibility of hydroxyapatite-coated titanium (HA/Ti) corneal implants at the molecular levels with histopathology. METHODS: Eighty Sprague-Dawley rats were divided into 2 equal groups. In the study group, HA/Ti prosthetics were implanted into the right corneal stroma. The control group received a sham incision. Corneas were collected and studied with histopathological examination (HE), immunohistochemical, and other stains, including scanned electron microscopy and reverse transcription-polymerase chain reaction, to evaluate inflammatory reactions, tissue repair, and expression of various biological factors during healing. RESULTS: In the control group, corneal neovascularization occurred 7 days after surgery, and the corneas recovered 28 days after surgery. In the study group, corneal vascularization increased substantially on day 7 and stabilized on day 28. For both groups, reverse transcription-polymerase chain reaction detected expressions of 6 primers at all time points. The amplified sequences were consistent with the designed sequences. The expression of matrix metalloproteinase-2, matrix metalloproteinase-9, bFGF, vascular endothelial growth factor, and type III collagen were delayed in the study group compared with the control group. Histological analyses showed a tight attachment of the corneal tissue to the HA/Ti implant on day 28. CONCLUSIONS: The HA/Ti corneal implants can remain stable in corneal tissue for a long time, induce corneal neovascularization, and stimulate inflammatory cells and keratocytes to synthesize or activate matrix metalloproteinases. Artificial cornea made from this material show enhanced stability and biocompatibility in vivo.

[Selection of landscape metrics for urban forest based on simulated landscapes].

Based on the existing urban forest landscape of Shenyang, four landscape pattern gradients were simulated, and one existing landscape pattern gradient in accordance with the trend of these gradients was selected. By analyzing the responses of 28 landscape metrics for landscape fragmentation and patch shape complexity to various landscape pattern gradients, preference landscape metrics were selected for describing the degree of the two landscape pattern characteristics. The results showed that patch density (PD) and mean patch area (AREA_MN) regularly responded to the change of landscape fragmentation. The increase of landscape fragmentation resulted in an increase of PD value while a decrease of AREA_MN value. Patch shape complexity of area weighted mean perimeter area ratio (PARA_AM) coincided with the gradients of landscape pattern. PARA AM value increased with increasing patch shape complexity, which precisely characterized the degree of patch shape complexity.

Importance of the ionic nature of ionic liquids in affecting enzyme performance.

The activity and stability of mushroom tyrosinase were studied in ionic liquid (IL)-containing aqueous systems. The effect of three ILs ([BMIm][PF(6)], [BMIm][BF(4)]), and [BMIm][MeSO(4)], where [BMIm] = 1-butyl-3-methylimidazolium) and their inorganic salts (KMeSO(4), KPF(6), and NaBF(4)) on the enzyme performance was investigated by comparing the kinetic (such as K(m), V(max), optimal pH and temperature, and activation energy) and thermostability parameters (including half-lives, deactivation constants, activation energies for enzyme deactivation, DeltaG*, DeltaH*, and DeltaS*) of the enzyme in the absence and presence of the ILs and their anions. Both the three ILs and their inorganic salts were able to trigger enzyme activation. The enzyme could be stabilized by addition of KMeSO(4) and NaBF(4) but destabilized by the presence of all the three ILs. The substrate selectivity of the enzyme was unchanged. The effect of ILs on enzyme performance can be largely attributed to their ionic nature via interaction with the enzyme structure, the substrate, and the water molecules associated with the enzyme, depending on their kosmotropocity, nucleophilicity, and H-bond basicity. The different influences brought from the ILs and their associated ions indicate the cooperative functioning of both cation and anion of the IL in affecting the enzyme performance.