Synergistic effects of silicon and goethite co-application in alleviating cadmium stress in rice (Oryza sativa L.): Insights into plant growth and iron plaque formation mechanisms.

Rice is one of the most important staple food crops; however, it is prone to cadmium (Cd) accumulation, which has negative health effects. Therefore, methods to reduce Cd uptake by rice are necessary. At present, there is limited research on the effects of co-application of silicon (Si) and goethite in mitigating Cd stress in rice. Furthermore, the specific mechanisms underlying the effects of their combined application on iron plaque formation in rice roots remain unclear. Therefore, this study analyzed the effects of the combined application of Si and goethite on the biomass, physiological stress indicators, Cd concentration, and iron plaques of rice using hydroponic experiments. The results revealed that co-treatment with both Si and goethite increased the plant height and dry weight, superoxide dismutase and catalase activities, photosynthetic pigment concentration, and root activity. Moreover, this treatment decreased the malondialdehyde concentration, repaired epidermal cells, reduced the Cd concentration in the roots by 57.2 %, and increased the number of iron plaques and Cd concentration by 150.9 % and 266.2 % in the amorphous and crystalline fractions, respectively. The Cd/Fe ratio in amorphous iron plaques also increased. Our findings suggest that goethite serves as a raw material for iron plaque formation, while Si enhances the oxidation capacity of rice roots. The application of a combination of Si and goethite increases the quantity and quality of iron plaques, enhancing its Cd fixation capacity. This study provides theoretical evidence for the effective inhibition of Cd uptake by iron plaques in rice, providing insights into methods for the remediation of Cd contamination.

Assessing lateral femoral condyle cartilage prior to medial UKA: MRI vs. Valgus stress radiograph.

BACKGROUND: The cartilage quality of the lateral compartment needs to be clarified prior to medial unicompartmental knee arthroplasty (UKA). Valgus stress radiograph has been recommended as the preferred tool. Some studies also show that magnetic resonance imaging (MRI) has a higher diagnostic value. So, we conducted this study to compare whether valgus stress radiographic lateral joint space width (LJSW) and MRI grading can accurately reflect cartilage quality and its screening value for UKA-suitable patients. METHODS: One hundred and thirty eight knees proposed for UKA were enrolled prospectively. Valgus stress radiograph was taken to measure LJSW. LJSW > 4 mm was considered normal and suitable for UKA. For weight-bearing area cartilage of lateral femoral condyle, Recht grade was assessed by MRI preoperatively. Recht grades ≤ 2 were treated as non-high-grade injuries while Recht grades > 2 were treated as high-grade injuries. Outerbridge grade was the gold standard and was assessed intraoperatively. Patients with Outerbridge grades 0-2 (non-high-grade injuries) underwent UKA, and patients with Outerbridge grades 3-4 (high-grade injuries) underwent total knee arthroplasty (TKA). The diagnostic parameters of valgus stress radiograph and MRI for the selection of UKA candidates were calculated, and receiver operating characteristic curves were drawn. P < 0.05 was considered significant. RESULTS: Of 138 knees, 120 underwent UKAs, and 18 underwent TKAs. In terms of selecting UKA candidates, the sensitivity was close between MRI (95.0%) and valgus stress radiograph (96.7%), and the specificity, accuracy, positive predictive value and negative predictive value of MRI (94.4%, 94.9%, 99.1%, 73.9%, respectively) were higher than that of valgus stress radiograph (5.9%, 85.5%, 88.0%, 20.0%, respectively). The difference in area under the curve (AUC) between MRI (0.950) and LJSW (0.602) was significant (P = 0.001). CONCLUSION: Compared with valgus stress radiograph, MRI has excellent evaluation value in diagnosing lateral weight-bearing cartilage injuries and can be used as a reliable tool for selecting suitable UKA patients.

How much the leg length has changed after the MOUKA through measurement of the full length radiographs? Beware of splicing error.

BACKGROUND: Leg length change after knee arthroplasty is one of the most concerned problems for patients and doctors. However, as there was only one literture focused on the leg length change after unicompartmental knee arthroplasty, we aimed to clarify the leg length change after medial mobile-bearing unicompartmental knee arthroplasty (MOUKA) using a novel double calibration method. METHODS: We enrolled patients who underwent MOUKA and had taken full-length radiographs in a standing position prior to and at 3 months after the operation. We eliminated the magnification by a calibrator and corrected the longitudinal splicing error by measuring the femur and tibia lengths before and after operation. Perceived leg length change was collected 3 months after operation. Bearing thickness, preoperative joint line convergence angle, preoperative and postoperative varus angles, flexion contracture and Oxford knee score (OKS) were also collected. RESULTS: From June 2021 to February 2022, 87 patients were enrolled.76 (87.4%) of them showed an increase with an average of 0.32 cm (range from -0.30 cm to 1.05 cm) in leg length change. The lengthening was strongly correlated with the degree of varus deformity and its correction value (r = 0.81&0.92, P < 0.01). Only 4 (4.6%) patients perceived leg length lengthening after operation. There was no difference in OKS between the patients who had an increase in leg length and those who had a decrease (P = 0.99). CONCLUSIONS: Majority of patients only experienced a slight increase in leg length after MOUKA, and such an increase did not affect patients' perception and short-term function.

Does diabetes mellitus increase the incidence of early thrombosis in deep vein following unicompartmental knee arthroplasty: a retrospective cohort study.

BACKGROUND: Many patients following unicompartmental knee arthroplasty (UKA) also suffer from diabetes mellitus, which may lead to an increased likelihood of postoperative deep venous thrombosis (DVT). Therefore, we evaluated whether DVT incidence would increase 3 days following UKA in diabetic patients. METHODS: Patients who underwent UKA from August 2018 to September 2021 in our hospital were retrospectively included. Age, gender, body mass index, hypertension, mode of anesthesia, surgery time, intraoperative blood loss, tourniquet pressure and time, and glycosylated hemoglobin concentration were recorded as confounders. We compared the incidence and type of DVT between non-diabetic and diabetic patients and evaluated the effect of glycosylated hemoglobin levels on DVT. RESULTS: Of all the 224 patients, 96 had diabetes and 128 did not. Within 3 days after surgery, DVT occurred in 25 cases in the diabetic group and 17 cases in the non-diabetic group (p < 0.05), and the difference mainly exists in the lower limbs on the surgical side. Logistic regression analysis demonstrated that the risk of DVT in the diabetic group was 4.50 times higher compared with the non-diabetic group. For every 1 unit increase of glycosylated hemoglobin, the incidence of DVT increased 2.35 times. Differences in age, gender, body mass index, hypertension, mode of anesthesia, surgery time, intraoperative blood loss, tourniquet pressure, and time between the two groups were not significant. CONCLUSIONS: The incidence of DVT in diabetic patients within 3 days after UKA was significantly higher than that in non-diabetic patients and was proportional to the concentration of glycosylated hemoglobin.

Does contemporary bicruciate retaining total knee arthroplasty restore the native knee kinematics? A descriptive literature review.

BACKGROUND: There has been no consensus on the benefit of retaining the anterior cruciate ligament (ACL) in TKAs. This study aims to review recent evidences around the kinematics of bicruciate retaining (BCR) total knee arthroplasty (TKA). MATERIALS AND METHODS: A search of the literature was conducted on PubMed and Web of Science. Reports that assessed the BCR TKA kinematics, including both in vitro cadaveric studies and in vivo clinical studies, were reviewed. RESULTS: A total number of 169 entries were obtained. By exclusion criteria, five in vitro studies using cadaveric knee specimens and six in vivo studies using patient cohorts were retained. In vitro studies showed a low internal rotation (< 10°) throughout the flexion path in all BCR TKAs. Compared to native knees, the difference in the internal rotation was maximal during early and late flexion; the femur in the BCR TKA was significantly more anteriorly positioned (1.7-3.6 mm from 0° to 110°) and more externally rotated (3.6°-4.2° at 110° and 120°). In vivo studies revealed that the native knee kinematics, in general, were not fully restored after BCR TKA during various knee activates (squatting, level-walking, and downhill-walking). There are asymmetric kinematics during the stance phase of gait cycle and a smaller range of axial rotation (23% patients exhibiting external tibial rotation) throughout the gait cycle in BCR TKAs. CONCLUSIONS: Critical insights in the complex BCR TKA biomechanics have been reported from recent laboratory kinematics studies. However, whether contemporary BCR TKAs can fully restore native knee kinematics remains debatable, warranting further investigations.

Slight cartilage damage in weight-bearing area of lateral femoral condyle do not compromise short-term outcomes of medial unicompartmental knee arthroplasty.

INTRODUCTION: Medial unicompartmental knee arthroplasty (mUKA) requires full-thickness cartilage in the lateral compartment, but slight damage of the cartilage surface can be ignored. However, as this statement lacks literature support, we investigated whether slight cartilage damages in the weight-bearing area of the lateral femoral condyle would affect the outcome of mUKAs. MATERIALS AND METHODS: Outerbridge grading was performed on the cartilage in the weight-bearing area of the lateral femoral condyle intraoperatively. The patients, grouped as normal or as having lateral condyle cartilage of Outerbridge grade 1-2 (slight cartilage damage), underwent mUKA. Full-length lower extremity radiographs were taken and hip-knee-ankle angles (HKAAs) were measured both preoperatively and postoperatively. Using magnetic resonance imaging, the lateral meniscal extrusion distance was also measured. In addition, the Oxford Knee Score (OKS) was assessed preoperatively and at the last follow-up, in addition to the patient satisfaction assessment. RESULTS: We enrolled 152 knees of 142 patients proposed for mUKAs. The mean age of participants was 69.5 years (51-89 years) and they were followed up for a mean of 25.4 months (15-44 months). There was no significant difference in preoperative (p = 0.746) and postoperative (p = 0.202) mean OKS between the normal, Outerbridge grade 1 and Outerbridge grade 2 groups. While the normal group had a higher change in OKS than the group with cartilage damage, this difference was not significant (p = 0.910). The UKA corrected the patients' mean HKAA from 171.1° (preoperatively) to 176.1° (postoperatively). From all patients, only four had slight lateral meniscus extrusion with MEDs of ≤ 0.25 mm. With the exception of one patient with a poor outcome in normal group, the rest were satisfied with the outcome of mUKA. No patients had prosthesis-related complications or revision surgery. CONCLUSIONS: Cartilage damage of Outerbridge grade 1 and grade 2 in the weight-bearing area of the lateral femoral condyle will not compromise the short-term outcome of medial mobile-bearing UKA.

Circ_0020093 ameliorates IL-1ß-induced apoptosis and extracellular matrix degradation of human chondrocytes by upregulating SPRY1 via targeting miR-23b.

Osteoarthritis (OA) is a chronic disease characterized by articular cartilage degeneration and uncontrolled chondrocyte apoptosis. At present, accumulating evidence introduces that circular RNA (circRNA) is involved in the development of OA. The aim of our study was to explore the role and the functional mechanism of circ_0020093 in OA cell model. Human chondrocytes were treated with interleukin-1 beta (IL-1ß) to construct OA model. The expression of circ_0020093, miR-23b, and Sprouty 1 (SPRY1) mRNA was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell apoptosis was assessed by flow cytometry assay. The expression of extracellular matrix (ECM)-associated markers and SPRY1 protein level was detected by qRT-PCR and Western blot. Bioinformatics analysis-predicted relationship between miR-23b and circ_0020093 or SPRY1 was further verified by dual-luciferase reporter assay and RNA pull-down assay. In this study, we found that the expression of circ_0020093 and SPRY1 was declined, while miR-23b expression was elevated in IL-1ß-treated chondrocytes. IL-1ß induced chondrocyte apoptosis and ECM degradation, while these negative effects were alleviated by circ_0020093 overexpression or miR-23b inhibition. MiR-23b was a target of circ_0020093, and SPRY1 was a downstream target of miR-23b. Rescue experiments showed that miR-23b enrichment reversed the role of circ_0020093 overexpression, and SPRY1 knockdown also reversed the effects of miR-23b inhibition. Importantly, circ_0020093 positively regulated SPRY1 expression by targeting miR-23b. In conclusion, circ_0020093 ameliorates IL-1ß-induced apoptosis and ECM degradation of human chondrocytes by regulating the miR-23b/SPRY1 axis.

Hybrid Oxford unicompartmental knee arthroplasty has lower residual cement extrusion than cemented arthroplasty in treating end-stage unicompartmental knee osteoarthritis.

BACKGROUND: Hybrid Oxford unicompartmental knee arthroplasty (OUKA) consists of cementless femoral prostheses and cemented tibial prostheses. Although a hybrid OUKA has been used in clinical practice, the clinical outcome has not been reported. The purpose of this study was to compare the short-term clinical outcomes and rate of residual bone cement extrusion between hybrid and cemented prostheses and analyse the possible reasons for differences between outcomes. METHODS: A total of 128 knees (118 patients) with end-stage osteoarthritis were included in this study, of which underwent consecutive operations using unicondylar Oxford phase 3 implants from July 2017 and September 2019 in our centre. Follow-up was performed at 6 weeks, 3 and 6 months, 1 year and every year after operation, and complications and changes in the Oxford knee score (OKS) were recorded. The OKS of the two groups was analysed by the generalized estimating equation approach. Prosthesis-based standard fluoroscopy was performed in a timely manner after each operation, and the rate of residual cement extrusion of the two groups was estimated using T-tests and a multivariate regression analysis. RESULTS: Excluding the cases that lost follow-up, a total of 120 knees (65 in hybrid group and 55 in cemented group) were included in the analysis. There was no statistically significant difference in patient characteristics between the two groups (p > 0.05). The average follow-up time was 23.4 months (and ranged from 12 to 38 months). As of the last follow-up, there were no complications, such as dislocation, fracture, prosthesis loosening and subsidence, but one patient in the cemented group experienced symptoms caused by residual loose cement. Postoperative OKS in both groups improved significantly (p < 0.001). There was no significant difference in the OKS at any point during the follow-up or in the improvement of the OKS between the two groups (p > 0.05). Residual cement was mainly extruded behind the tibial prosthesis. The rate of hybrid periprosthetic residual cement extrusion was significantly lower in the hybrid group than in the cemented group, and the difference was statistically significant (OR = 3.38; p = 0.014). CONCLUSIONS: Hybrid OUKA is as effective as cemented OUKA in the short term after operation and can significantly reduce the residual cement extrusion rate around the tibial prosthesis.

An elderly female with adult-onset Still's disease initially misdiagnosed as prosthetic joint infection after total knee arthroplasty: lessons in differential diagnosis and treatment.

BACKGROUND: High fever, knee swelling and pain after knee arthroplasty are often considered as symptoms of acute prosthetic joint infection. However, similar symptoms can also present as primary manifestations of adult-onset Still's disease, which creates some interference in differential diagnosis. To our knowledge, this is the first published case of misdiagnosis of adult Still's disease after total knee arthroplasty, who was initially misdiagnosed as an prosthetic joint infection due to the above-mentioned symptoms. The symptoms of the knee infection was not relieve after several revisions and continous antibiotic treatment. Finally, after several consultations and repeated evaluation it was diagnosed as adult-onset Still's disease. CASE PRESENTATION: A 77-year-old female who underwent bilateral total knee arthroplasty 6 years ago was admitted to our hospital with high fever, right knee effusion and painful knee. Based on the results of joint fluid aspiration and culture, we treated the right knee as acute hematogenous prosthetic joint infection. After three debridement and revision surgeries, the patient's symptoms continued to persist. Subsequent manifestations of other symptoms such as typical rash and sore throat and laboratory examination suggested the possibility of adult-onset Still's disease. So she underwent diagnostic steroid hormone therapy at the recommendation of a rheumatologist, and a final revision was performed after symptom was controlled. At the one-year follow-up, the patient's symptoms completely resolved and the knee revision was functioning well. CONCLUSIONS: When joint swelling and pain occurs after knee arthroplasty, the possibility of joint infection should not only be considered, but rheumatic autoimmune diseases should also be differentiated. Because the manifestations of joint infection and rheumatic immune disease sometimes overlap highly, when reasonable treatment over a period of time fails to relieve symptoms and signs, we should notice subtle differences in symptoms and laborotary tests and look for other diagnostic possibilities in time.

Patient outcomes in Anteromedial osteoarthritis patients over 80 years old undergoing Oxford Unicompartmental knee Arthroplasty in China.

BACKGROUND: The use of Oxford Unicompartmental Knee Arthroplasty (UKA) has increased rapidly in both Western and Asian populations, with excellent functional outcomes and high patient satisfaction. While previous evidence regarding clinical outcomes and survival rates after Oxford UKA was based on studies in Western populations, the results may be different in Asian patients. The relevance of age for postoperative function after Oxford UKA also remains unclear. Hence, the aim of our study was to clarify the effectiveness and safety of Oxford UKA in Asian patients aged over 80 years. METHODS: A retrospective review was performed and included 195 patients (209 knees) who underwent an Oxford UKA between June 2015 and July 2018. We divided the patients into three groups by age: Group 1, 60-69 years; Group 2, 70-79 years; and Group 3, over 80 years. We used the Hospital for Special Surgery (HSS) score and Western Ontario and McMaster (WOMAC) Universities Osteoarthritis Index score to evaluate the general condition of the patients' knees before surgery and at last follow-up. We also recorded perioperative and short-term complications. RESULT: Group 1 consisted of 60 patients (60 knees); Group 2, 70 patients (79 knees); and Group 3, 65 patients (70 knees). The mean follow-up was 21.34 ± 12.04, 22.08 ± 11.38, and 21.76 ± 10.20 months in groups 1, 2, and 3, respectively. At last follow-up, the patients in Group 3 showed lower function scores compared to groups 1 and 2 (P < 0.05), but the HSS scores and the WOMAC scores were significantly improved in all three groups. In terms of perioperative and other complications, the three age groups did not differ significantly. CONCLUSION: Oxford UKA is an effective and safe treatment for osteoarthritis, even in elderly patients in China. Elderly patients have lower knee function scores than younger patients. However, the knee joint pain of the elderly patients was relieved and function improved compared to the preoperative condition.

Stair Climbing and High Knee Flexion Activities in Bi-Cruciate Retaining Total Knee Arthroplasty: In Vivo Kinematics and Articular Contact Analysis.

BACKGROUND: Bi-cruciate retaining (BCR) total knee arthroplasty (TKA) preserves both anterior and posterior cruciate ligaments with the potential to restore normal posterior femoral rollback and joint kinematics. However, there is limited information regarding articular contact behavior in the contemporary BCR TKA design during high knee flexion activities. This study aimed to investigate the articular knee contact performance in unilateral BCR TKA patients during strenuous flexion activities. METHODS: Twenty-nine unilateral BCR TKA patients were evaluated for both knees during single deep lunges, step-ups, and sit-to-stand (STS) using a validated combined computer tomography and dual fluoroscopic imaging system. Medial and lateral condylar contact positions were quantified during weight-bearing flexion. RESULTS: Contact excursions of the lateral condyle in BCR TKAs were significantly more anteriorly located than the contralateral non-operated knees during STS (-4.9 ± 3.1 vs -9.7 ± 4.6 mm, P < .05), single deep lunge (-5.7 ± 3.2 vs -10.0 ± 4.5 mm, P < .05), and step-ups (-4.8 ± 3.6 vs -9.1 ± 3.9 mm, P < .05). Contact points of BCR TKAs indicated reduced femoral external rotation during STS (2.1 ± 4.8° vs 7.7 ± 5.4°, P < .05), single deep lunges (1.8 ± 4.8° vs 7.0 ± 7.1°, P < .05), and step-ups (0.1 ± 4.1° vs 6.2 ± 4.9°, P < .05). Medial pivoting patterns were observed in only 59%, 56%, and 48% of the BCR TKA knees for step-ups, STS, and single deep lunge, respectively. CONCLUSION: The contemporary BCR TKA design demonstrated asymmetric femoral rollback, medial translation, as well as lateral pivoting in about half of the patient cohort, suggesting that in vivo tibiofemoral kinematic parameters were not fully restored in BCR patients during strenuous flexion activities.

Mismatch in elevational shifts between satellite observed vegetation greenness and temperature isolines during 2000-2016 on the Tibetan Plateau.

Climate warming on the Tibetan Plateau tends to induce an uphill shift of temperature isolines. Observations and process-based models have both shown that climate warming has resulted in an increase in vegetation greenness on the Tibetan Plateau in recent decades. However, it is unclear whether the uphill shift of temperature isolines has caused greenness isolines to shift upward and whether the two shifts match each other. Our analysis of satellite observed vegetation greenness during the growing season (May-Sep) and gridded climate data for 2000-2016 documented a substantial mismatch between the elevational shifts of greenness and temperature isolines. This mismatch is probably associated with a lagging response of greenness to temperature change and with the elevational gradient of greenness. The lagging response of greenness may be associated with water limitation, resources availability, and acclimation. This lag may weaken carbon sequestration by Tibetan ecosystems, given that greenness is closely related to primary carbon uptake and ecosystem respiration increases exponentially with temperature. We also found that differences in terrain slope angle accounted for large spatial variations in the elevational gradient of greenness and thus the velocity of elevational shifts of greenness isolines and the sensitivity of elevational shifts of greenness isolines to temperature, highlighting the role of terrain effects on the elevational shifts of greenness isolines. The mismatches and the terrain effect found in this study suggest that there is potentially large micro-topographical difference in response and acclimation/adaptation of greenness to temperature changes in plants. More widespread in situ measurements and fine-resolution remote sensing observations and fine-gridded climate data are required to attribute the mismatch to specific environmental drivers and ecological processes such as vertical changes in community structure, plant physiology, and distribution of species.

Administration of CoCl2 Improves Functional Recovery in a Rat Model of Sciatic Nerve Transection Injury.

Peripheral nerve injury is known to activate the hypoxia-inducible factor-1α (HIF-1α) pathway as one of pro-regenerative transcriptional programs, which could stimulate multiple injury-induced gene expression and contribute to axon regeneration and functional recovery. However, the role of HIF-1α in peripheral nerve regeneration remains to be fully elucidated. In this study, rats were divided into three groups and treated with sham surgery, surgery with cobalt chloride (CoCl2) and surgery with saline, respectively. Sciatic functional index, morphologic evaluations of muscle fibers, and never conduction velocity were performed to measure the functional recovery at 12 weeks postoperatively. In addition, the effects of CoCl2 on the expression of HIF-1α, glial cell line-derived neurotrophic factor (GDNF), brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) were determined at mRNA levels; as well as HIF-1α, the dual leucine zipper kinase (DLK), the c-Jun N-terminal kinase (JNK), phosphorylated JNK (p-JNK), BDNF and NGF were measured at protein level at 4 weeks postoperatively. Systemic administration of CoCl2 (15 mg/kg/day intraperitoneally) significantly promoted functional recovery of rats with sciatic nerve transection injury. This study demonstrated in rats treated with CoCl2, the expression of HIF-1α, GDNF, BDNF and NGF was significantly increased at mRNA level, while HIF-1α, DLK, p-JNK, BDNF and NGF was significantly increased at protein level.

Assessing plant senescence reflectance index-retrieved vegetation phenology and its spatiotemporal response to climate change in the Inner Mongolian Grassland.

Plant phenology is a key link for controlling interactions between climate change and biogeochemical cycles. Satellite-derived normalized difference vegetation index (NDVI) has been extensively used to detect plant phenology at regional scales. Here, we introduced a new vegetation index, plant senescence reflectance index (PSRI), and determined PSRI-derived start (SOS) and end (EOS) dates of the growing season using Moderate Resolution Imaging Spectroradiometer data from 2000 to 2011 in the Inner Mongolian Grassland. Then, we validated the reliability of PSRI-derived SOS and EOS dates using NDVI-derived SOS and EOS dates. Moreover, we conducted temporal and spatial correlation analyses between PSRI-derived SOS/EOS date and climatic factors and revealed spatiotemporal patterns of PSRI-derived SOS and EOS dates across the entire research region at pixel scales. Results show that PSRI has similar performance with NDVI in extracting SOS and EOS dates in the Inner Mongolian Grassland. Precipitation regime is the key climate driver of interannual variation of grassland phenology, while temperature and precipitation regimes are the crucial controlling factors of spatial differentiation of grassland phenology. Thus, PSRI-derived vegetation phenology can effectively reflect land surface vegetation dynamics and its response to climate change. Moreover, a significant linear trend of PSRI-derived SOS and EOS dates was detected only at small portions of pixels, which is consistent with that of greenup and brownoff dates of herbaceous plant species in the Inner Mongolian Grassland. Overall, PSRI is a useful and robust metric in addition to NDVI for monitoring land surface grassland phenology.

Strong impacts of daily minimum temperature on the green-up date and summer greenness of the Tibetan Plateau.

Understanding vegetation responses to climate change on the Tibetan Plateau (TP) helps in elucidating the land-atmosphere energy exchange, which affects air mass movement over and around the TP. Although the TP is one of the world's most sensitive regions in terms of climatic warming, little is known about how the vegetation responds. Here, we focus on how spring phenology and summertime greenness respond to the asymmetric warming, that is, stronger warming during nighttime than during daytime. Using both in situ and satellite observations, we found that vegetation green-up date showed a stronger negative partial correlation with daily minimum temperature (Tmin ) than with maximum temperature (Tmax ) before the growing season ('preseason' henceforth). Summer vegetation greenness was strongly positively correlated with summer Tmin , but negatively with Tmax . A 1-K increase in preseason Tmin advanced green-up date by 4 days (P < 0.05) and in summer enhanced greenness by 3.6% relative to the mean greenness during 2000-2004 (P < 0.01). In contrast, increases in preseason Tmax did not advance green-up date (P > 0.10) and higher summer Tmax even reduced greenness by 2.6% K(-1) (P < 0.05). The stimulating effects of increasing Tmin were likely caused by reduced low temperature constraints, and the apparent negative effects of higher Tmax on greenness were probably due to the accompanying decline in water availability. The dominant enhancing effect of nighttime warming indicates that climatic warming will probably have stronger impact on TP ecosystems than on apparently similar Arctic ecosystems where vegetation is controlled mainly by Tmax . Our results are crucial for future improvements of dynamic vegetation models embedded in the Earth System Models which are being used to describe the behavior of the Asian monsoon. The results are significant because the state of the vegetation on the TP plays an important role in steering the monsoon.

Exploring the copper(II)-aminotriazole complex-binding sites of human serum albumin.

The potential impact on human exposure to aminotriazole (ATA) and heavy metal in the environment becomes a concerning issue. In the current study, a water-soluble Cu(II)-aminotriazole complex [Cu(II)-ATA] was synthesized. To explore the binding mechanism of the complex with human serum albumin (HSA), their effects on conformation and activity of HSA by multispectroscopic approach and molecular modeling were investigated. Further fluorescent tests revealed that the quenching mechanism of HSA by Cu(II)-ATA was overall static. Meanwhile, the obtained binding constant and thermodynamic parameters on complex-HSA interaction showed that the types of interaction force of Cu(II)-ATA and HSA were hydrogen bonding, van der Waals and electrostatic. The analysis of three-dimensional fluorescence, circular dichroism and Fourier transform infrared spectroscopy showed that Cu(II)-ATA induced the changes in the secondary structure of HSA. Molecular docking simulation was performed and docking model suggested that the complex docked into HSA at subdomain IIA. Furthermore, amino group and attractive electrostatic interaction of Cu(II)-ATA greatly contributed to the hydrogen bonding, van der Waals and electrostatic interaction between Cu(II)-ATA and HSA, as confirmed by experimental data.

Temperature and snowfall trigger alpine vegetation green-up on the world's roof.

Rapid temperature increase and its impacts on alpine ecosystems in the Qinghai-Tibetan Plateau, the world's highest and largest plateau, are a matter of global concern. Satellite observations have revealed distinctly different trend changes and contradicting temperature responses of vegetation green-up dates, leading to broad debate about the Plateau's spring phenology and its climatic attribution. Large uncertainties in remote-sensing estimates of phenology significantly limit efforts to predict the impacts of climate change on vegetation growth and carbon balance in the Qinghai-Tibetan Plateau, which are further exacerbated by a lack of detailed ground observation calibration. Here, we revealed the spatiotemporal variations and climate drivers of ground-based herbaceous plant green-up dates using 72 green-up datasets for 22 herbaceous plant species at 23 phenological stations, and corresponding daily mean air temperature and daily precipitation data from 19 climate stations across eastern and southern parts of the Qinghai-Tibetan Plateau from 1981 to 2011. Results show that neither the continuously advancing trend from 1982 to 2011, nor a turning point in the mid to late 1990s as reported by remote-sensing studies can be verified by most of the green-up time series, and no robust evidence for a warmer winter-induced later green-up dates can be detected. Thus, chilling requirements may not be an important driver influencing green-up responses to spring warming. Moreover, temperature-only control of green-up dates appears mainly at stations with relatively scarce preseason snowfall and lower elevation, while coupled temperature and precipitation controls of green-up dates occur mostly at stations with relatively abundant preseason snowfall and higher elevation. The diversified interactions between snowfall and temperature during late winter to early spring likely determine the spatiotemporal variations of green-up dates. Therefore, prediction of vegetation growth and carbon balance responses to global climate change on the world's roof should integrate both temperature and snowfall variations.

Acute and chronic toxic effects of bisphenol A on Chlorella pyrenoidosa and Scenedesmus obliquus.

The acute and chronic toxic effects of Bisphenol A (BPA) on Chlorella pyrenoidosa (C. pyrenoidosa) and Scenedesmus obliquus (S. obliquus) were not well understood. The indoor experiments were carried out to observe and analyze the BPA-induced changes. Results of the observations showed that in acute tests BPA could significantly inhibit the growth of both algae, whereas chronic exposure hardly displayed similar trend. Superoxide dismutase (SOD) and Catalase (CAT) activities of both algae were promoted in all the treatments. Chlorophyll a synthesis of the two algae exhibited similar inhibitory trend in short-term treatments, and in chronic tests C. pyrenoidosa hardly resulted in visible influence, whereas in contrast, dose-dependent inhibitory effects of S. obliquus could be clearly observed. The experimental results indicated that the growth and Chlorophyll a syntheses of S.obliquus were more sensitive in response to BPA than that of C. pyrenoidosa, whereas for SOD andCAT activities, C. pyrenoidosa was more susceptible. This research provides a basic understanding of BPA toxicity to aquatic organisms.

[Traffic injuries of pre-hospital treatment in the urban area of Beijing].

OBJECTIVE: To evaluate the current condition of urban road traffic injuries (RTIs) according to Beijing Emergency Medical Center (BEMC) from Jan. 1, 2004 to Dec. 31, 2010, analyze the social characteristics and explore the possible methods for prevention and improvement. METHODS: Using data from the Beijing Emergency Medical Center, we collected 19 550 victims who were involved in RTIs in Beijing from Jan. 1, 2004 to Dec. 31, 2010. The personal information, time of the injury event, road user type and striking vehicle type, as well as the site and severity of injury, were analyzed using Excel 2007 and SPSS 17.0 software with ANOVA of variance and Chi-squared tests. RESULTS: The annual rate of RTIs was 120.0 per 100 000 people in Beijing, and the mortality rate was about 4.97 per 100 000 people. Male victims were more than female victims (11 737 persons vs. 7 618 persons).The mean age was (72.92 ± 5.67) years. Overall, RTIs in all the age groups happened in October commonly, and were inclined to daytime, especially at noon. But different age groups had their special hour distribution features of RTIs. Traffic collisions occurred most frequently in pedestrians and cyclists (7 588,38.81%;3 790,19.39%). Majorities of victims presented with head injuries and lower-limb injuries(8 343,42.68%; 6 828,34.93%). These collisions included car striking accidents (11 490, 58.77%). And most of the older adults were classified as medium in severity (11 718, 59.94%). CONCLUSION: The prevention and treatment of RTIs, should focus on targeted prevention solutions and standardized pre-hospital rescue, according to specific population, time interval and vehicle usage.

HIF-1α Induced by Hypoxia Promotes Peripheral Nerve Injury Recovery Through Regulating Ferroptosis in DRG Neuron.

Peripheral nerve injury (PNI) usually has a poor effect on functional recovery and severely declines the patient's quality of life. Our prior findings indicated that hypoxia remarkably promoted nerve regeneration of rats with sciatic nerve transection. However, the underlying molecular mechanisms of hypoxia in functional recovery of PNI still remain elusive. In this research, we tried to explain the functional roles and mechanisms of hypoxia and the hypoxia-inducible factor-1α (HIF-1α) in PNI. Our results indicated that hypoxia promoted proliferation and migration of dorsal root ganglia (DRG) and increased the expression of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF). Mechanistically, hypoxia suppressed ferroptosis through activating HIF-1α in DRG neurons. Gain and loss of function studies were performed to evaluate the regulatory roles of HIF-1α in ferroptosis and neuron recovery. The results revealed that up-regulation of HIF-1α enhanced the expression of solute carrier family membrane 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) and increased the contents of cysteine and glutathione, while inhibiting the accumulation of reactive oxygen species (ROS). Our findings provided novel light on the mechanism of ferroptosis involved in PNI and manifest hypoxia as a potential therapeutic strategy for PNI recovery.