ATP homeostasis and signaling in plants.

ATP is the primary form of energy for plants, and a shortage of cellular ATP is generally acknowledged to pose a threat to plant growth and development, stress resistance, and crop quality. The overall metabolic processes that contribute to the ATP pool, from production, dissipation, and transport to elimination, have been studied extensively. Considerable evidence has revealed that in addition to its role in energy supply, ATP also acts as a regulatory signaling molecule to activate global metabolic responses. Identification of the eATP receptor DORN1 contributed to a better understanding of how plants cope with disruption of ATP homeostasis and of the key points at which ATP signaling pathways intersect in cells or whole organisms. The functions of SnRK1α, the master regulator of the energy management network, in restoring the equilibrium of the ATP pool have been demonstrated, and the vast and complex metabolic network mediated by SnRK1α to adapt to fluctuating environments has been characterized. This paper reviews recent advances in understanding the regulatory control of the cellular ATP pool and discusses possible interactions among key regulators of ATP-pool homeostasis and crosstalk between iATP/eATP signaling pathways. Perception of ATP deficit and modulation of cellular ATP homeostasis mediated by SnRK1α in plants are discussed at the physiological and molecular levels. Finally, we suggest future research directions for modulation of plant cellular ATP homeostasis.

Quality in screening and measuring blood pressure in China's primary health care: a national cross-sectional study using unannounced standardized patients.

Background: This study aims to evaluate primary care providers' adherence to the standard of measuring blood pressure for people aged 35 or above during their initial visit, as per Chinese guidelines, and to identify factors affecting their practices. Methods: We developed 11 standardized patients (SP) cases as tracer conditions to evaluate primary care, and deployed trained SPs for unannounced visits to randomly selected providers in seven provinces of China. The SPs used a checklist based on guidelines to record whether and how blood pressure was measured. Data were analyzed descriptively and regression analysis was performed to examine the association between outcomes and factors such as provider, patient, facility, and clinical case characteristics. Findings: The SPs conducted 1201 visits and found that less than one-third of USPs ≥35 had their blood pressure measured. Only 26.9% of migraine and 15.4% of diabetes cases received blood pressure measurements. Additionally, these measurements did not follow the proper guidelines and recommended steps. On average, 55.6% of the steps were followed with few providers considering influencing factors before measurement and only 6.0% of patients received both-arm measurements. The use of wrist sphygmomanometers was associated with poor blood pressure measurement. Interpretation: In China, primary care hypertension screening practices fall short of guidelines, with infrequent initiation of blood pressure measurements and inadequate adherence to proper measurement steps. To address this, priority should be placed on adopting, implementing, and upholding guidelines for hypertension screening and measurement. Funding: National Natural Science Foundation of China, Swiss Agency for Development and Cooperation, Doctoral Fund Project of Inner Mongolia Medical University, China Postdoctoral Science Foundation.

Improving eye care quality through brief verbal intervention on optometry service provider by using unannounced standardized patient with refractive error: study protocol for a randomized controlled trial.

BACKGROUND: Improper refractive correction can be harmful to eye health, aggravating the burden of vision impairment. During most optometry clinical consultations, practitioner-patient interactions play a key role. Maybe it is feasible for patients themselves to do something to get high-quality optometry. But the present empirical research on the quality improvement of eye care needs to be strengthened. The study aims to test the effect of the brief verbal intervention (BVI) through patients on the quality of optometry service. METHODS: This study will take unannounced standardized patient (USP) with refractive error as the core research tool, both in measurement and intervention. The USP case and the checklist will be developed through a standard protocol and assessed for validity and reliability before its full use. USP will be trained to provide standardized responses during optical visits and receive baseline refraction by the skilled study optometrist who will be recruited within each site. A multi-arm parallel-group randomized trial will be used, with one common control and three intervention groups. The study will be performed in four cities, Guangzhou and three cities in Inner Mongolia, China. A total of 480 optometry service providers (OSPs) will be stratified and randomly selected and divided into four groups. The common control group will receive USP usual visits (without intervention), and three intervention groups will separately receive USP visits with three kinds of BVI on the patient side. A detailed outcome evaluation will include the optometry accuracy, optometry process, patient satisfaction, cost information and service time. Descriptive analysis will be performed for the survey results, and the difference in outcomes between interventions and control providers will be compared and statistically tested using generalized linear models (GLMs). DISCUSSION: This research will help policymakers understand the current situation and influencing factors of refractive error care quality, and then implement precise policies; at the same time, explore short and easy interventions for patients to improve the quality of optometry service. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2200062819. Registered on August 19, 2022.

Exploration of Multi-Gene DNA Barcode Markers to Reveal the Broad Genetic Diversity of Field Ticks (Acari: Ixodidae) in a Tropical Environment of Hainan Island, China.

Ticks are hematophagous arthropods and obligate ectoparasites of humans and other animals. This study focused on the molecular discrimination of ticks in the tropical environment of Hainan according to multi-gene DNA barcode markers with the expectation of accurately distinguishing species. A total of 420 ticks, including 49 adult ticks, 203 nymphal ticks, and 168 larval ticks, were collected in the field, and the 49 adult ticks were identified as Rhipicephalus turanicus, Dermacentor marginatus, and Haemaphysalis longicornis. The mitochondrial 16S rRNA, ribosomal 28S rRNA D2, and ribosomal internal transcribed spacer 2 (ITS2) regions were used as DNA barcode markers to discriminate species. According to basic local alignment search tool analysis against the GenBank database, 16S rRNA positively identified ticks in the Rhipicephalus, Dermacentor, and Haemaphysalis genera; the 28S rRNA D2 region identified ticks in the Rhipicephalus and Dermacentor genera; and ITS2 identified ticks as D. marginatus. Pairwise sequence comparisons based on these three regions were visualized with a Sequence Demarcation Tool matrix. Substitution saturation tests using data analysis and molecular biology and evolution revealed little substitution saturation (Iss < Iss.c, p < 0.05) in the 16S rRNA region for the Haemaphysalis genus; 28S rRNA D2 region for the Rhipicephalus, Dermacentor, and Haemaphysalis genera; and ITS2 region for the Rhipicephalus and Dermacentor genera. Distinctive sequences for which it is difficult to obtain good matches with the sequences available in GenBank exist in the ticks of Hainan. Future studies should obtain complementary sequences to refine and update the database for the molecular characterization of ticks.

Validity of patients' online reviews at direct-to-consumer teleconsultation platforms: a protocol for a cross-sectional study using unannounced standardised patients.

INTRODUCTION: As direct-to-consumer teleconsultation (hereafter referred to as 'teleconsultation') has gained popularity, an increasing number of patients have been leaving online reviews of their teleconsultation experiences. These reviews can help guide patients in identifying doctors for teleconsultation. However, few studies have examined the validity of online reviews in assessing the quality of teleconsultation against a gold standard. Therefore, we aim to use unannounced standardised patients (USPs) to validate online reviews in assessing both the technical and patient-centred quality of teleconsultations. We hypothesise that online review results will be more consistent with the patient-centred quality, rather than the technical quality, as assessed by the USPs. METHODS AND ANALYSIS: In this cross-sectional study, USPs representing 11 common primary care conditions will randomly visit 253 physicians via the three largest teleconsultation platforms in China. Each physician will receive a text-based and a voice/video-based USP visit, resulting in a total of 506 USP visits. The USP will complete a quality checklist to assess the proportion of clinical practice guideline-recommended items during teleconsultation. After each visit, the USP will also complete the Patient Perception of Patient-Centeredness Rating. The USP-assessed results will be compared with online review results using the intraclass correlation coefficient (ICC). If ICC >0.4 (p<0.05), we will assume reasonable concordance between the USP-assessed quality and online reviews. Furthermore, we will use correlation analysis, Lin's Coordinated Correlation Coefficient and Kappa as supplementary analyses. ETHICS AND DISSEMINATION: This study has received approval from the Institutional Review Board of Southern Medical University (#Southern Medical Audit (2022) No. 013). Results will be actively disseminated through print and social media, and USP tools will be made available for other researchers. TRIAL REGISTRATION: The study has been registered at the China Clinical Trials Registry (ChiCTR2200062975).

Clinical application of whole exome sequencing technology in small-for-gestational-age children.

AIM: To apply whole exome sequencing (WES) for molecular diagnosis of small-for-gestational-age (SGA) children. METHODS: We retrospectively analyzed the data of 60 SGA children in our hospital, and performed developmental assessment, laboratory tests, imaging tests, and whole exome sequencing (WES), which were combined with clinical phenotypes to clarify the pathogenicity of the variant genes in the children. RESULTS: Sixty SGA children were tested, and pathogenic SGA was detected at relatively high frequencies on chromosomes 7, 8, and 22. Of these, karyotype analysis clearly suggested developmental disorders in 4 patients. Also, a case of Wiedemann-Steiner syndrome due to a de novo nonsense variant in the KMT2A gene was detected. CONCLUSIONS: The use of WES testing technology to increase the diagnosis rate of children with special SGA is conducive to the correct diagnosis and treatment of such children.

Titanium nitride as a promising sodium-ion battery anode: interface-confined preparation and electrochemical investigation.

The search for new electrode materials for sodium-ion batteries (SIBs), especially for enhancing the specific capacity and cycling stability of anodes, is of great significance for the development of new energy conversion and storage materials. Here, a new type of titanium nitride composite anode (TiN@C) coated with 2D carbon nanosheets was prepared for the first time using a rationally designed topochemical conversion approach of interface-confinement. Subsequently, the electrochemical performance and Na+ storage mechanism of TiN@C as an anode for SIBs was investigated. The quantum-dot-sized TiN anodes exhibited shorter ionic transport pathways, while the 2D ultrathin carbon nanosheets reinforced the structural stability of the composite and provided a high electron transformation rate. As a result, the TiN/C composite anode can deliver a high reversible capacity of 170 mA h g-1 and 149 mA h g-1 after 5000 cycles at a current density of 0.5 A g-1 and 1 A g-1, indicating excellent electrochemical properties. This work provides new opportunities to explore the convenient and controllable preparation of metal nitride anodes for other energy conversion and storage applications.

First Report of Brown Spot of Dekopon Fruit Caused by Cladosporium tenuissimum in China.

Dekopon citrus (Citrus reticulata Shiranui) is a three-way hybrid (Citrus unshiu Marcov. × C. sinensis Osbeck × C. reticulata Blanco) developed in Japan in 1972. This citrus is popular in China due to its sweet and tender taste (Lim 2012). In November of 2021, a brown spot disease on Dekopon fruits with about 20% disease incidence was observed in an orchard of the Institute of Citrus Research in Ganzhou, Jiangxi Province, China. Initially, the symptoms appeared as slightly sunken deep red to purple spots on the fruit surface, with the disease progression, lesions became brown to brown-black large necrotic regions covered with a fluffy layer of gray spores. Infected fruits were surface sterilized with 70% ethanol for 30 sec and rinsed three times with sterile distilled water. Diseased tissues from the edge of lesions were cut into small segments, placed onto potato dextrose agar and incubated at 25℃ for 7 days. Ten single-spore isolates were obtained in total. Fungal colonies were olive green to dark green, velvet-like in texture and sporulated abundantly, surrounded by grayish-white hyphae. Conidiophores were subcylindrical, straight, septate, solitary or in clusters of two to three, and ranged in size from 65 to 550 × 3.8 to 6.3 µm (x ̅= 261.7 ± 60.5 × 5.2 ± 0.4 µm, n=50). Ramoconidia were cylindrical，aseptate, and 10 to 22 × 2.8 to 4.5 µm (x ̅= 15.5 ± 1.4 × 4.0 ± 0.9 µm, n=50). Conidia were lemon-shaped to oval-shaped, smooth-walled, and 1.8 to 5.0 × 1.4 to 2.5 µm (x ̅= 3.9 ± 0.4 × 2.2 ± 0.2 µm, n=50). The morphological characteristics of the pathogen were consistent with those of Cladosporium tenuissimum Cooke (Li et al. 2021). For further identification, DNA was extracted from two representative isolates. The internal transcribed spacer (ITS) region, translation elongation factor (EF1-α), and actin (ACT) were amplified by using primers ITS1/ITS4, EF1-728F/EF1-986R, and ACT-512F/ACT-783R (Bensch et al. 2012), respectively. ITS (OM232067, OM232068), EF1-α (OM256525, OM256526) and ACT (OM256529, OM256530) sequences were deposited in GenBank. Multi-gene (combined data set of ITS, EF1-α and ACT) phylogenetic analysis was conducted using the Maximum Likelihood method (Nguyen et al. 2015). Based on the morphological characteristics and the molecular data, two fungal isolates were identified as C. tenuissimum. To evaluate pathogenicity, fifteen fruits were surface sterilized with 1% NaClO solution for 30 sec, rinsed twice with sterile distilled water and dried. Dekopon fruits (n=10) were wounded with a sterile needle and inoculated with a 10 µL drop of conidial suspension (1 × 106 conidia/mL) of isolate GZCJ-1, followed by incubation at 25℃ and 80% relative humidity. The controls (n=5) were treated with sterile water and maintained under the same conditions. Five days after inoculation, small brown sunken spots were observed on the wounded and inoculated fruits. After 7 days, lesions were coated by a layer of brown conidia that were similar to those described above, whereas control remained symptomless. Pathogenicity test was repeated twice. Cladosporium tenuissimum was consistently re-isolated from inoculated fruits and confirmed by morphological and molecular data, fulfilling the Koch's postulates. To our knowledge, this is the first report of C. tenuissimum causing the brown spot of dekopon fruit in China and perhaps the world. The disease may become the potential risk for fruit production, making fruits unfit for marketing purposes, and the appropriate management actions will be necessary.

Superstructured Nanocrystals/Dual-Doped Mesoporous Carbon Anodes for High-Performance Sodium-Ion Batteries.

Two-dimensional ordered superstructures have been attracting considerable attention due to their interesting properties and potential applications. However, designing ideal functional superstructures with excellent electrochemical properties is still a major challenge, and an in-depth understanding of the structure-activity relationship of electrodes remains to be achieved. To elucidate this critical issue, herein, we rationally designed and synthesized for the first time superstructured TiO2/dual-doped mesoporous carbon anodes using confined space and surface coassembly strategies. Our method primarily relied on the larger interlayer space few-layered MXene and its negatively charged surface, allowing hexamethylenetetramine intercalation and surface electrostatic adsorption. The superstructured TiO2/dual-doped mesoporous carbon was successfully assembled by the thermal decomposition of a confined carbon precursor. Subsequently, the comparison of Na+-storage properties of various anodes was carried out based on the results of structural characterization techniques and electrochemical analysis methods. The results showed that the optimized anode (N/O-C@TiO2-20) can deliver a reversible capacity of 165 mA h g-1 after 1000 cycles at a current density of 1 A g-1, indicating excellent electrochemical properties. The enhancement can be attributed to the synergistic effect of carbon domains, defective nanocrystals, and a covalently coupled interface between TiO2 and mesoporous carbon. Our work not only offered a new strategy for the assembly and regulation of superstructures to promote the electrochemical performance but also enlightened the rational design of advanced anodes for sodium-ion battery application.

Significance of serum glucagon-like peptide-1 and matrix Gla protein levels in patients with diabetes and osteoporosis.

BACKGROUND: Osteoporosis is a systemic bone disease characterized by decreased bone mass, impaired bone mass, and reduced bone strength that leads to increased bone fragility and fracture. Type 2 diabetes mellitus (T2DM) complicated with osteoporosis is a common systemic metabolic bone disease, and reduced bone mass and bone strength are considered the main clinical features; however, the pathogenesis of this disease has not been fully clarified. Its occurrence is considered related to sex, age, and genetic factors. There are many risk factors for diabetes complicated with osteoporosis. Therefore, exploring these risk factors will help prevent it. AIM: To investigate the relationships among serum glucagon-like peptide-1 (GLP-1) levels, matrix Gla protein (MGP) levels, and diabetes with osteoporosis. METHODS: Sixty patients with T2DM complicated with osteoporosis confirmed by the endocrinology department of our hospital were selected as the case group. Sixty T2DM patients with bone loss were selected as the control group. Sixty healthy participants were selected as the healthy group. The general data, bone mineral density index, and bone metabolic markers of the three groups were compared. The relationships among GLP-1 levels, MGP levels, and the bone mineral density index of the case group were analyzed using linear correlation analysis and a logistic regression model. RESULTS: Differences in sex, smoking, and drinking among the case group, control group, and healthy group were not statistically significant (P > 0.05). The mean age of the case group was older than those of the control and healthy groups (P < 0.05). The body mass index, fasting plasma glucose level, HbA1c level, hypertension rate, and coronary heart disease rate of the case and control groups were higher than those of the healthy group (P < 0.05). The serum GLP-1 and MGP levels of the case group were lower than those of the control and healthy groups; these differences were statistically significant (P < 0.05). The serum GLP-1 and MGP levels of the control group were lower than those of the healthy group; these differences were statistically significant (P < 0.05). The serum GLP-1 and MGP levels of the case group were significantly positively correlated with the bone mineral density values of the hip and lumbar spine (P < 0.05). The results of the logistic regression model showed that age and duration of diabetes were independent risk factors for osteoporosis in diabetic patients (P < 0.05) and that increased GLP-1 and MGP values were protective factors against osteoporosis in diabetic patients (P < 0.05). CONCLUSION: Serum GLP-1 and MGP levels of diabetic patients with osteoporosis were significantly decreased and positively correlated with bone mineral density and were independent risk factors for osteoporosis in diabetic patients.

Risk and protection strategies of Amolops wuyiensis intestine against gastrointestinal nematode (Cosmocercoides wuyiensis n. sp.) infection.

Anuran amphibians are susceptible to infection by intestinal nematodes, but the damage and response mechanisms that occur in their intestines after infection are only partially understood. In this study, the intestinal disruption and response mechanisms in Amolops wuyiensis frogs infected with Cosmocercoides wuyiensis n. sp. were revealed through analysis of the intestinal histopathology, digestive enzyme activity, transcriptome and intestinal microbiota. Tissue section analysis showed histological damage and inflammation in the infected intestine, and the digestive enzyme activity indicated a decrease in digestion and absorption of some nutrients. We found that infection led to differences in the intestinal microbiota composition, including lower diversity and symbiotic relationships. The greater relative abundance of the genera Burkholderia and Rhodococcus may enhance intestinal immunity to resist pathogenic infections. A comparison of the transcriptomes of infected and uninfected intestines revealed 1055 differentially expressed genes. GO enrichment and KEGG pathways analyses suggested that the guts of infected C. wuyiensis n. sp. show enhanced complement activation, cell adhesion molecule function, NOD-like receptor signalling pathway activity and other innate immunity responses. Among the adaptive immune responses, the intestinal immune network for IgA production was significantly enriched, and the expression of IL-17D and transforming growth factor beta-1 genes were upregulated in the infected intestine. These results imply that C. wuyiensis n. sp. infection of A. wuyiensis intestine may trigger innate and adaptive immune responses, which reduce the post-infection burden. Furthermore, the intestine of A. wuyiensis may also respond to C. wuyiensis n. sp. infection by increasing metallocarboxypeptidase activity and accelerating smooth muscle contraction.

Efficacy of auto-aggregating aerobic denitrifiers with coaggregation traits for bioaugmentation performance in biofilm-formation and nitrogen-removal.

To promote efficiency nitrogen-rich wastewater treatment from a sequencing batch biofilm reactor (SBBR), three aerobic denitrifiers (Pseudomonas mendocinaIHB602, Methylobacterium gregansDC-1 and Pseudomonas stutzeriIHB618) with dual-capacities of strong auto-aggregation and high nitrogen removal efficiency were studied. The aggregation index analysis indicated that coaggregation of the three strains co-existed was better when compared with one or two strains grown alone. Optimal coaggregation strains were used to bioaugmente a test reactor (SBBRT), which exhibited a shorter time for biofilm-formation than uninoculated control reactor (SBBRC). With different influent ammonia-N loads (150, 200 and 300 mg·L-1), the average ammonia-N and nitrate-N removal efficiency were all higher than that in SBBRC, as well as a lower nitrite-N accumulation. Microbial community structure analysis revealed coaggregation strains may successfully colonize in the bioreactor and be very tolerant of high nitrogen concentrations, and contribute to the high efficiency of inorganic nitrogen-removal and biofilm-formation.

Transoral Endoscopic Thyroidectomy Vestibular Approach Versus Endoscopic Thyroidectomy Via Areola Approach for Patients With Unilateral Papillary Thyroid Carcinoma: A Retrospective Study.

BACKGROUND: Endoscopic thyroidectomy via areola approach (ETA) has been widely used in thyroidectomy for many years as it can effectively avoid a scar in the neck. Transoral endoscopic thyroidectomy vestibular approach (TOETVA) is newly applied and has gained popularity quickly. This study is to compare the safety and effectiveness of TOETVA and ETA. MATERIALS AND METHODS: A total of 95 patients who underwent TOETVA or ETA with unilateral papillary thyroid carcinoma were enrolled in this study from March 2019 to February 2020. The basic information (such as gender, age), intraoperative hemorrhage, postoperative drainage volume, hospital durations, intraoperative and postoperative complications, operative time, central lymph node dissection time, total number of central lymph nodes, and number of metastatic central lymph nodes were compared. RESULTS: The operative time of the TOETVA group was significantly longer than the ETA group (148.11±19.78 vs. 135.90±12.77 min, P<0.05). However, the result was opposite when central lymph node dissection time was compared (10.31±2.93 vs. 12.48±3.55, P<0.05). TOETVA had an advantage on total number of central lymph nodes over ETA (7.82±3.35 vs. 5.26±2.45, P<0.05). No differences were found between the 2 groups on other data. CONCLUSION: TOETVA and ETA have the similarity on surgical safety and effectiveness. TOETVA has its advantage on central lymph node dissection and might be a reasonable alternative for ETA and open surgery in the future.

Hepatitis B Virus Affected Serum MicroRNA-203a Level in Hepatocellular Carcinoma.

BACKGROUND: MicroRNAs have been shown to play a critical role in early diagnosis of hepatocellular carcinoma. Nevertheless, microRNAs' functions in serum of patients with hepatocellular carcinoma (HCC) are not fully understood. METHODS: qRT-PCR was used to detect the expression level of microRNA-203a (miR-203a) in clinical serum samples of HCC and HepG2 cells. Kaplan-Meier method was used to estimate overall survival, and the cell scratch test was used to observe the migration ability of cells in vitro. RESULTS: Here, we first observed that serum miR-203a was significantly upregulated in HCC patients with HBV compared to without HBV. In HCC patients, miR-203a low expression was positively related with poor overall survival. In addition, we found that HBV improved the poor prognosis of HCC patients with lower miR-203a levels. After successfully constructing HepG2 cell line carrying HBV, further studies demonstrated miR-203a expression level was increased in HepG2 with HBV compared to without HBV. CONCLUSIONS: Lower serum miR-203a level in HCC patients led to worse overall survival, which depended on HBV. In vitro, miR-203a level was positively correlated with HBV. Therefore, our studies provided the novel insight into the role of serum miR-203a in HCC patients with HBV and potential new molecular target for early diagnosis of hepatitis B virus-related hepatocellular carcinoma.

Fabrication of High-Performance Magnetic Lysozyme-Imprinted Microsphere and Its NIR-Responsive Controlled Release Property.

The preparation of efficient and practical biomacromolecules imprinted polymer materials is still a challenging task because of the spatial hindrance caused by the large size of template and target molecules in the imprinting and recognition process. Herein, we provided a novel pathway to coat a NIR-light responsive lysozyme-imprinted polydopamine (PDA) layer on a fibrous SiO2 (F-SiO2) microsphere grown up from a magnetic Fe3O4 core nanoparticle. The magnetic core-shell structured lysozyme-imprinted Fe3O4@F-SiO2@PDA microspheres (MIP-lysozyme) can be easily separated by a magnet and have a high saturation adsorption capacity of lysozyme of 700 mg/g within 30 min because of the high surface area of 570 m(2)/g and the mesopore size of 12 nm of the Fe3O4@F-SiO2 support. The MIP-lysozyme microspheres also show an excellent selective adsorption of lysozyme (IF > 4). The binding thermodynamic parameters studied by ITC proves that the lysozyme should be restricted by the well-defined 3D structure of MIP-lysozyme microspheres. The MIP-lysozyme can extract lysozyme efficiently from real egg white. Owing to the efficient NIR light photothermal effect of PDA layer, the MIP-lysozyme microspheres show the controlled release property triggered by NIR laser. The released lysozyme molecules still maintain good bioactivity, which can efficiently decompose E. coli. Therefore, this work provides a novel strategy to build practical NIR-light-responsive MIPs for the extraction and application of biomacromolecules.

Fabrication of fibrous amidoxime-functionalized mesoporous silica microsphere and its selectively adsorption property for Pb(2+) in aqueous solution.

Fibrous cyano-modified mesoporous SiO2 microspheres with specific surface area of ca. 300 m(2) g(-1) have been successfully fabricated respectively by in-situ synthesis and post-modification methods, based on the hydrolysis of ethyl silicate in the presence of (2-cyanoethyl)triethoxysilane at a certain condition. TEM observations show that the average diameters of the prepared fibrous cyano-modified SiO2 microspheres by these two methods are 68 and 211 nm, respectively. The N2 adsorption-desorption isotherms analysis on the fibrous SiO2 microspheres show sharp peaks in the 10-20 nm range. After the cyano groups transformed to amidoxime groups, the adsorption behavior of the fibrous amidoxime-functionalized mesoporous SiO2 microspheres for Fe(3+), Cu(2+), and Pb(2+) was investigated. The results show that the prepared SiO2 microspheres can selectively adsorb Pb(2+). The maximum equilibrium adsorption capacity for Pb(2+) could reach 284 mg/g. The desorption of Pb(2+) in 2M HNO3 completes within 60 min. The efficiency of the desorption is as high as 96.2%. This work provides the methods to prepare amidoxime-functionalized SiO2 microsphere with high specific surface area and total pore volume, which has the potential to be applied as an efficient adsorbent for specific heavy metal ions.

[Effect of the interaction of microorganisms and iron oxides on arsenic releasing into groundwater in Chinese Loess].

A large part of groundwater in the Chinese Loess Plateau area is characterized by high arsenic concentration. Anaerobic bacteria have been considered to play key roles in promoting arsenic releasing from loess to groundwater. However, this hypothesis remains unconfirmed. Based on modeling experiments, this study investigated the speciation of arsenic in loess, and then determined the release rates and quantities of arsenic with the mediation of anaerobic bacteria. The results showed that arsenic contents in loess were between 23 mg.kg-1 and 30 mg.kg-1. No obvious arsenic content difference among loess samples was observed. The ratios for specific adsorbed, iron oxides co-precipitated and silicate co-precipitated arsenic were 37.76% , 36. 15% and 25. 69% , respectively. Indigenous microorganisms, dissimilatory iron reducing bacteria (DIRB) and sulfate reducing bacteria (SRB) could all promote the release of arsenic from loess. Organic matters highly affected the release rates. More than 100 mg.L-1 sodium lactate was required for all bacterial experiments to facilitate obvious arsenic release. Considering the redox condition in loess, the contribution of SRB to arsenic release in loess area was less feasible than that of DIRB and indigenous microorganisms.