Recent advances in palladium-catalyzed sulfonylation via SO2 insertion.

The importance of sulfonyl-group-containing compounds, such as sulfonamides, sulfones, sulfinate esters, and sulfonyl fluorides, in pharmaceuticals, bioactive molecules, and natural products cannot be overstated. The new development of palladium-catalyzed sulfonylation via SO2 insertion represents a crucial advancement in organic synthesis, enabling the direct α,α-difunctionalization of SO2 and providing efficient access to an array of structure-diverse sulfonyl-containing compounds. Although there have been numerous reviews about SO2 insertion, many of them only cover specific aspects of palladium-catalyzed reactions, leading to an oversight of some important works. Besides, these reviews often lack detailed discussions and systematic conclusion on reaction mechanisms, and fail to comprehensively summarize the significant research achievements in palladium-catalyzed reactions over the past few years. Herein, we aim to systematically consolidate the recent advances in palladium-catalyzed sulfonylation via SO2 insertion, elucidate the underlying reaction mechanism, and highlight some unsolved challenges in this segment. This review seeks to serve as a valuable resource for researchers, assisting in the continued development of palladium-catalyzed sulfonylation methodologies.

Safety of prone emergence from general endotracheal anesthesia in patients undergoing ERCP: a randomized controlled trial.

BACKGROUND: Conventional supine emergence and prone extubation from general endotracheal anesthesia (GEA) are associated with extubation-related adverse events (ERAEs). Given the minimally invasive nature of endoscopic retrograde cholangiopancreatography (ERCP) as well as the improved ventilation/perfusion matching and easier airway opening in the prone position, we aimed to assess the safety of prone emergence and extubation in patients undergoing ERCP under GEA. METHODS: Totally, 242 eligible patients were recruited and randomized into the supine extubation group (n = 121; supine group) and the prone extubation group (n = 121; prone group). The primary endpoint was the incidence of ERAEs during emergence, including hemodynamic fluctuations, coughing, stridor, and hypoxemia requiring airway maneuvers. The secondary endpoints included the incidence of monitoring disconnections, extubation time, recovery time, room exit time, and post-procedure sore throat. RESULTS: The incidence of ERAEs was significantly lower in the prone group compared with the supine group (8.3% vs 34.7%, OR = 0.17, 95% CI 0.18-0.56; P < 0.001). Moreover, the prone group demonstrated no monitoring disconnections, shorter extubation time and room exit time, faster recovery, and, lower frequency and milder sore throat after the procedure. CONCLUSIONS: For patients undergoing ERCP under GEA, compared with supine, prone emergence, and extubation had remarkably lower rates of EAREs and better recovery, and can maintain continuous monitoring and improve efficiency.

The discovery and utilization of favorable genes in Oryza longistaminata.

Asian cultivated rice has been domesticated from ancestors of the wild rice species Oryza rufipogon. During this process, important changes have occurred in many agronomic traits, such as plant height, grain shattering, and panicle shape, and the yield has also greatly increased. However, many favored traits (e.g., stress resistance) have been lost. The genome of O. longistaminata is of the same AA type as O. sativa, harboring many genes conferring resistance to biotic and abiotic stresses, and it is considered as a potential gene pool for genetic improvement of O. sativa. In this review, we summarize the basic research on O. longistaminata, including its resistance to biotic and abiotic stresses, its rhizome traits, and other traits that are of potential application value, such as bacterial blight resistance, drought resistance, heat tolerance, self-incompatibility, nitrogen efficiency, and high yield. Furthermore, we present the current applied research progress on perennial rice breeding based on the rhizome trait of O. longistaminata. Lastly, the possibility of de novo domestication of O. longistaminata is discussed. We expect this article to provide information to enhance the basic research of O. longistaminata and accelerate the genetic improvement of cultivated rice.

Neutrophil to lymphocyte ratio as prognostic and predictive factor in patients with coronavirus disease 2019: A retrospective cross-sectional study.

This retrospective study was designed to explore whether neutrophil to lymphocyte ratio (NLR) is a prognostic factor in patients with coronavirus disease 2019 (COVID-19). A cohort of patients with COVID-19 admitted to the Tongren Hospital of Wuhan University from 11 January 2020 to 3 March 2020 was retrospectively analyzed. Patients with hematologic malignancy were excluded. The NLR was calculated by dividing the neutrophil count by the lymphocyte count. NLR values were measured at the time of admission. The primary outcome was all-cause in-hospital mortality. A multivariate logistic analysis was performed. A total of 1004 patients with COVID-19 were included in this study. The mortality rate was 4.0% (40 cases). The median age of nonsurvivors (68 years) was significantly older than survivors (62 years). Male sex was more predominant in nonsurvival group (27; 67.5%) than in the survival group (466; 48.3%). NLR value of nonsurvival group (median: 49.06; interquartile range [IQR]: 25.71-69.70) was higher than that of survival group (median: 4.11; IQR: 2.44-8.12; P < .001). In multivariate logistic regression analysis, after adjusting for confounding factors, NLR more than 11.75 was significantly correlated with all-cause in-hospital mortality (odds ratio = 44.351; 95% confidence interval = 4.627-425.088). These results suggest that the NLR at hospital admission is associated with in-hospital mortality among patients with COVID-19. Therefore, the NLR appears to be a significant prognostic biomarker of outcomes in critically ill patients with COVID-19. However, further investigation is needed to validate this relationship with data collected prospectively.

[Values of Apparent Diffusion Coefficient and Fractional Anisotropy in the Diagnosis of Brucella Spondylitis].

Objective To compare the differences in apparent diffusion coefficient (ADC) and fractional anisotropy (FA) between brucella spondylitis (BS) groups at different stages before treatment and the normal control group and to evaluate the change trend of ADC value and FA value at different time points before and after treatment. Methods Totally 53 patients suspected of BS by conventional magnetic resonance imaging (MRI) and later confirmed as BS patients by serological tests were enrolled in this study. These patients underwent conventional MRI and diffusion tensor imaging scans,and the ADC value and FA value were measured. Independent sample t test was used to compare the ADC value and FA value between the BS group and the control group,the ADC value and FA value between the BS group at each stage. Repeated measurement ANOV was used to compare the ADC values and FA values at different time points before and after treatment. Results FA imaging showed that the color code of BS was different from that of the normal control group,and the color code of FA imaging showed increased singal. The ADC values of BS in the acute,subacute,and chronic stages [(1.45±0.02)×10 -3 mm 2/s,(1.35±0.03)×10 -3 mm 2/s,(1.26±0.05)×10 -3 mm 2/s,respectively] were significantly higher than those in the control group [(1.06±0.09) ×10 -3 mm 2/s](t=2.538,P=0.009;t=1.998,P=0.032;t=1.575,P=0.004),and the FA value (0.55±0.02,0.65±0.03,0.71±0.04,respectively) were significantly lower than those of the control group (0.78±0.02) (t=2.440,P=0.012; t=1.847,P=0.041;t=2.102,P=0.003). Repeated measurement analysis showed that there were statistically significant differences in ADC values and FA values at different time points before and after treatment in the acute,subacute,and chronic stages (ADC:F=12.100,P<0.001;F=8.439,P=0.005;F=9.704,P=0.004,respectively;FA:F=7.080,P=0.002;F=6.607;P=0.003;F=8.868,P=0.001,respectively). The ADC values at different time points after treatment were significantly lower than those before treatment or at a previous time point after treatment (F=332.14,P<0.001),and the FA values were significantly higher than those before treatment or at a previous time point after treatment (F=134.26,P<0.001). Conclusions FA color code can intuitively display differences in BS and normal vertebral bodies and show change of color code before and after treatment. Also,the ADC values and FA values can quantitatively reveal differences between BS and normal vertebral body in different time points and quantify BS vertebral lesion changes before and after treatment. In particular,in BS patients who are recovering from treatment,it can quantify microscopic edema. Therefore,diffusion tensor imaging may be useful objective indicator in evaluating the effectiveness of a specific treatment for BS.

MOV10 inhibits replication of porcine reproductive and respiratory syndrome virus by retaining viral nucleocapsid protein in the cytoplasm of Marc-145 cells.

Porcine reproductive and respiratory syndrome virus (PRRSV) has been a major threat to global industrial pig farming ever since its emergence in the late 1980s. Identification of sustainable and effective control measures against PRRSV transmission is a pressing problem. The nucleocapsid (N) protein of PRRSV is specifically localized in the cytoplasm and nucleus of virus-infected cells which is important for PRRSV replication. In the current study, a new host restricted factor, Moloney leukemia virus 10-like protein (MOV10), was identified as an inhibitor of PRRSV replication. N protein levels and viral replication were significantly reduced in Marc-145 cells stably overexpressing MOV10 compared with those in wild-type Marc-145 cells. Adsorption experiments revealed that MOV10 did not affect the attachment and internalization of PRRSV. Co-immunoprecipitation and immunofluorescence co-localization analyses showed that MOV10 interacted and co-localized with the PRRSV N protein in the cytoplasm. Notably, MOV10 affected the distribution of N protein in the cytoplasm and nucleus, leading to the retention of N protein in the former. Taken together, these findings demonstrate for the first time that MOV10 inhibits PRRSV replication by restricting the nuclear import of N protein. These observations have great implications for the development of anti-PRRSV drugs and provide new insight into the role of N protein in PRRSV biology.

Dual-Carbon-Confined Fe7 S8 Anodes with Enhanced Electrochemical Catalytic Conversion Process for Ultralong Lithium Storage.

Although the electrochemical catalytic conversion process is effective in increasing the reversible capacity of lithium-ion batteries, the low contact efficiency between metal catalyst and substrate and pulverization of the solid electrolyte interface (SEI) film without protection are not beneficial for the electrochemical reactions. Herein, Fe7 S8 nanoparticles are confined by both reduced graphene oxide (RGO) and in-situ-formed amorphous carbon (C) to form dual-carbon-confined Fe7 S8 as a lithium-ion anode. The dual-carbon-confined structure provides a confined space to prevent pulverization of the SEI film and increases the local concentration of intermediate phases, which could be electrocatalytically decomposed by Fe nanoparticles formed in situ to increase the reversibility of the electrochemical reactions and gain high reversible capacity. In addition, the dual-carbon-confined structure ensures fast transfer of electrons and boosts transport of lithium ions due to the highly conductive dual-carbon shell. Thus, the Fe7 S8 /C/RGO anode delivers an excellent rate performance and long cycling stability. At current densities of 2000 and 5000 mA g-1 , the reversible capacities are 520 mA h g-1 over 1500 cycles and 294 mA h g-1 over 2000 cycles, respectively.

[Diffusion Tensor Imaging in Early Diagnosis and Prognostic Prediction of Intervertebral Disc Change in Patients with Brucella Spondylitis].

Objective To explore the value of fractional anisotropy(FA) and apparent diffusion coefficient(ADC) in the early diagnosis of intervertebral disc change in patients with Brucella spondylitis(BS) and in the assessment of BS disc changes after treatment and to further investigate the imaging features of BS in its acute,subacute,and chronic stages. Methods Totally 60 serologically or pathologically confirmed BS patients who were treated in the First Hospital Affiliated to Hebei North University(n=20) or ZhangJiakou Infectious Diseases Hospital(n=40) were enrolled. BS patients were scanned by CT,magnetic resonance imaging,and diffusion tensor imaging,and the FA and ADC values of the disc were measured using the DTI Fiber Trak package. The FA and ADC values were compared in each period and after treatment. Results The ADC value significantly increased and the FA value significantly decreased in different stages(P<0.01). Six months after treatment,the ADC value was significantly lower than the pre-treatment,and the FA value was significantly increased(P<0.01). The ADC value 12 months after treatment for patients in acute or subacute stage and the FA value 12 months after treatment for patients in all stages were significantly different from those in the 6th month after treatment(P<0.01),and the only exception was that the ADC value in the chronic stage was not significantly different between 12th and 6th month after treatment(P=0.089).Conclusion FA and ADC values are more sensitive than conventional MRI sequences in the diagnosis of BS intervertebral disc change and therefore can be used for the early diagnosis and prognostic prediction.

[Enzymatic glycosylation of 4'-demethylepipodophyllotoxin].

The glycosides of 4'-demethylepipodophyllotoxin (DMEP) possess various pharmacological activities; however, the chemical synthesis of these glycosides faces challenges in regioselectivity, stereoselectivity, and the protection and de-protection of functional groups. In this work, a novel glycosyltransferase (GT) gene AbGT5 from Aloe barbadensis was successfully cloned, heterogeneously expressed and purified. Recombinant AbGT5 was able to catalyze the glycosylation of DMEP and the glycosylated product, which was separated from the preparative scale reaction, was characterized as DMEP 4'-O-ß-D-glucoside via MS, 1H-NMR, 13C-NMR, HSQC and HMBC. According to the investigations of enzyme properties, AbGT5 show the highest activity around 20 ℃ in the buffer of pH 9.0, and it was independent of divalent metal ions. Under the optimum conditions, the conversion rate of DMEP can reach 80%. Above all, in this work the enzymatic glycosylation of DMEP was achieved with high efficiency by the novel GT AbGT5.

Comparison of the pulmonary dead-space fraction derived from ventilator volumetric capnography and a validated equation in the survival prediction of patients with acute respiratory distress syndrome.

PURPOSE: This prospective observational study aims to evaluate the accuracy of dead-space fraction derived from the ventilator volumetric capnography (volumetric CO2) or a prediction equation to predict the survival of mechanically ventilated patients with acute respiratory distress syndrome (ARDS). METHODS: Consecutive VD/VT measurements were obtained based upon a prediction equation validated by Frankenfield et al for dead-space ventilation fraction: VD/VT = 0.320 + 0.0106 (PaCO2-ETCO2)⁺ 0.003 (RR)⁺0.0015 (age) in adult patients who had infection-related severe pneumonia and were confirmed as having ARDS. Here PaCO2 is the arterial partial pressure of carbon dioxide in mmHg; ETCO2, the end- tidal carbon dioxide measurement in mmHg; RR, respiratory rate per minute; and age in years. Once the patient had intubation, positive end expiratory pressure was adjusted and after Phigh reached a steady state, VD/VT was measured and recorded as the data for the first day. VD/VT measurement was repeated on days 2, 3, 4, 5 and 6. Meanwhile we collected dead-space fraction directly from the ventilator volu- metric CO2 and recorded it as Vd/Vt. We analyzed the changes in VD/VT and Vd/Vt over the 6-day period to determine their accuracy in predicting the survival of ARDS patients. RESULTS: Overall, 46 patients with ARDS met the inclusion criteria and 24 of them died. During the first 6 days of intubation, VD/VT was significantly higher in nonsurvivors on day 4 (0.70 ± 0.01 vs 0.57 ± 0.01), day 5 (0.73 ± 0.01 vs. 0.54 ± 0.01), and day 6 (0.73 ± 0.02 vs. 0.54 ± 0.01) (all p =0.000). Vd/Vt showed no significant difference on days 1e4 but it was much higher in nonsurvivors on day 5 (0.45 ± 0.04 vs. 0.41 ± 0.06) and day 6 (0.47 ± 0.05 vs. 0.40 ± 0.03) (both p=0.008). VD/VT on the fourth day was more accurate to predict survival than Vd/Vt. The area under the receiver-operating characteristic curve for VD/VT and Vd/Vt in evaluating ARDS patients survival was day 4 (0.974 ± 0.093 vs. 0.701 ± 0.023, p = 0.0024) with the 95% confidence interval being 0.857-0.999 vs. 0.525-0.841. CONCLUSION: Compared with Vd/Vt derived from ventilator volumetric CO2, VD/VT on day 4 calculated by Frankenfield et al's equation can more accurately predict the survival of ARDS patients.

Mechanisms of fluoroquinolone resistance in Mycobacterium tuberculosis.

Tuberculosis, caused by the pathogen Mycobacterium tuberculosis, is one of the world's deadliest bacterial infectious disease. It is still a global-health threat, particularly because of the drug-resistant forms. Fluoroquinolones, with target of gyrase, are among the drugs used to treat tuberculosis. However, their widespread use has led to bacterial resistance. The molecular mechanisms of fluoroquinolone resistance in mycobacterium tuberculosis have been reported, such as DNA gyrase mutations, drug efflux pumps system, bacterial cell wall thickness and pentapeptide proteins (MfpA) mediated regulation of gyrase. Mutations in gyrase conferring quinolone resistance play important roles and have been extensively studied. Recent studies have shown that the regulation of DNA gyrase affects mycobacterial drug resistance, but the mechanisms, especially by post-translational modification and regulatory proteins, are poorly understood. In this review, we summarize the fluoroquinolone drug development, and the molecular genetics of fluoroquinolone resistance in mycobacteria. Comprehensive understanding of the mechanisms of fluoroquinolone resistance in Mycobacterium tuberculosis will open a new view on understanding drug resistance in mycobacteria and lead to novel strategies to develop new accurate diagnosis methods.

Upregulated dynamin 1 in an acute seizure model and in epileptic patients.

Dynamin 1 is a neuron-specific guanosine triphosphatase (GTPase) that is an essential component of membrane fission during synaptic vesicle recycling and endocytosis. This study evaluated the dynamin 1 expression pattern in the acute lithium-pilocarpine rat model and in patients with temporal lobe epilepsy (TLE) and investigated whether altering the dynamin 1 expression pattern affects epileptic seizures in vivo and in vitro. The immunofluorescence, western blot analysis, and reverse transcription-PCR results show that the dynamin 1 expression level increased significantly in experimental rats from day 1 to day 7 after the onset of seizures and was significantly higher in TLE patients. The behavioral study revealed that inhibiting dynamin 1 increased the latency time of the first seizure and decreased the frequency and severity of the seizures. In addition, electrophysiological recordings from brain slices showed that inhibiting dynamin 1 reduces the frequency of Mg-free induced seizure-like activity. The anticonvulsant effect of dynasore was more effective at 10 µM than at 1 µM or 160 µM. These results indicate that the altered level of dynamin 1 may contribute to the development of epileptic seizures and that the targeted regulation of dynamin 1 activity may control epileptic seizures.

Electrocardiogram score for the selection of reperfusion strategy in early latecomers with ST-segment elevation myocardial infarction.

OBJECTIVE: The clinical benefit of percutaneous coronary intervention (PCI) is controversial in ST-segment elevation myocardial infarction (STEMI) patients presenting 12-72 hours after symptom onset. Several studies suggested this conflicting result was associated with myocardial area at risk (MaR) of enrolled patients. MaR could be estimated by the electrocardiogram (ECG) score. Our objective was to evaluate the benefits of PCI in STEMI latecomers with different MaR. METHODS: We constructed a prospective cohort involving 436 patients presenting 12-72 hours after STEMI onset and who met an inclusion criteria. 218 underwent PCI and 218 received the optimal medical therapy (OMT) alone. Individual MaR was quantified by the combined Aldrich ST and Selvester QRS score. The primary endpoint was a composite of cardiovascular death, reinfarction or revascularization within two years. RESULTS: The 2-year cumulative primary endpoint rate was respectively 9.2% in PCI group and 5.3% in OMT group when MaR<35% (adjusted hazard ratio for PCI vs. OMT, 1.855; 95% confidence interval [CI], 0.617-5.575; P=0.271), and was 12.8% in PCI group and 23.1% in OMT group when MaR ≥35% (adjusted hazard ratio for PCI vs. OMT, 0.448; 95% CI, 0.228-0.884; P=0.021). CONCLUSION: The benefit of PCI for the STEMI latecomers was associated with the MaR. PCI, compared with OMT, could significantly reduce the 2-year primary outcomes in patients with MaR≥35%, but not in ones with MaR<35%.

Effects of moderate static magnetic fields on the voltage-gated sodium and calcium channel currents in trigeminal ganglion neurons.

AIM: To study the effects of static magnetic fields (SMF) on the electrophysiological properties of voltage-gated sodium and calcium channels on trigeminal ganglion (TRG) neurons. METHODS: Acutely dissociated TRG neurons of neonatal SD rats were exposed to 125-mT and 12.5-mT SMF in exposure devices and whole-cell patch-clamp recordings were carried out to observe the changes of voltage-gated sodium channels (VGSC) and calcium channels (VGCC) currents, while laser scanning confocal microscopy was used to detect intracellular free Ca(2+) concentration in TRG neurons, respectively. RESULTS: (1) No obvious change of current-voltage (I-V) relationship and the peak current densities of VGSC and VGCC currents were found when TRG neurons were exposed to 125-mT and 12.5-mT SMF. However, the activation threshold, inactivation threshold and velocity of the channel currents above were significantly altered by 125-mT and 12.5-mT SMF. (2) The fluctuation of intracellular free Ca(2+) concentration within TRG neurons were slowed by 125-mT and 12.5-mT SMF. When SMF was removed, the Ca(2+) concentration level showed partial recovery in the TRG neurons previously exposed by 125-mT SMF, while there was a full recovery found in 12.5-mT-SMF-exposed neurons. CONCLUSIONS: Moderate-intensity SMF could affect the electrophysiological characteristics of VGCS and VGCC by altering their activation and inactivation threshold and velocity. The fluctuations of intracellular free Ca(2+) caused by SMF exposure were not permanent in TRG neurons.

The phenotype and tissue-specific nature of multipotent cells derived from human mature adipocytes.

Dedifferentiated fat (DFAT) cells derived from mature adipocytes have been considered to be a homogeneous group of multipotent cells, which present to be an alternative source of adult stem cells for regenerative medicine. However, many aspects of the cellular nature about DFAT cells remained unclarified. This study aimed to elucidate the basic characteristics of DFAT cells underlying their functions and differentiation potentials. By modified ceiling culture technique, DFAT cells were converted from human mature adipocytes from the human buccal fat pads. Flow cytometry analysis revealed that those derived cells were a homogeneous population of CD13(+) CD29(+) CD105(+) CD44(+) CD31(-) CD34(-) CD309(-) α-SMA(-) cells. DFAT cells in this study demonstrated tissue-specific differentiation properties with strong adipogenic but much weaker osteogenic capacity. Neither did they express endothelial markers under angiogenic induction.

Auditory sexual difference in the large odorous frog Odorrana graminea.

Acoustic communication is an important behavior in frog courtship. Male and female frogs of most species, except the concave-eared torrent frog Odorrana tormota, have largely similar audiograms. The large odorous frogs (Odorrana graminea) are sympatric with O. tormota, but have no ear canals. The difference in hearing between two sexes of the frog is unknown. We recorded auditory evoked near-field potentials and single-unit responses from the auditory midbrain (the torus semicircularis) to determine auditory frequency sensitivity and threshold. The results show that males have the upper frequency limit at 24 kHz and females have the upper limit at 16 kHz. The more sensitive frequency range is 3-15 kHz for males and 1-8 kHz for females. Males have the minimum threshold at 11 kHz (58 dB SPL), higher about 5 dB than that at 3 kHz for females. The best excitatory frequencies of single units are mostly between 3 and 5 kHz in females and at 7-8 kHz in males. The underlying mechanism of auditory sexual differences is discussed.

The effectiveness of intervention in hepatitis C patients and improvement in their referral rate.

BACKGROUND: To investigate the effectiveness of the intervention with critical value management and push short messaging service (SMS), and to determine improvement in the referral rate of patients with positive hepatitis C antibody (anti-HCV). METHODS: No intervention was done for patients with positive anti-HCV screening results from 1 January 2015 to 31 October 2021. Patients with positive anti-HCV results at our hospital from 1 November 2021 to 31 July 2022 were informed vide critical value management and push SMS. For inpatients, a competent physician was requested to liaise with the infectious disease physician for consultation, and patients seen in the OPD (outpatient department) were asked to visit the liver disease clinic. The Chi-square correlation test, one-sided two-ratio test and linear regression were used to test the relationship between intervention and referral rate. RESULTS: A total of 638,308 cases were tested for anti-hepatitis C virus (HCV) in our hospital and 5983 of them were positive. 51.8% of the referred patients were aged 18-59 years and 10.8% were aged ≥75 years. The result of Chi-square correlation test between intervention and referral was p = .0000, p < .05. One-sided two-ratio test was performed for statistics of pre-intervention referral rate (p1) and post-intervention referral rate (p2). Normal approximation and Fisher's exact test for the results obtained were 0.000, p < .05, and the alternative hypothesis p1 - p2 < 0 was accepted. The linear regression equation was referral = 0.1396 × intervention + 0.3743, and the result model p = 8.79e - 09, p < .05. The model was significant, and the coefficient of intervention was 0.1396. CONCLUSIONS: The interventions of critical value management and push SMS were correlated with the referral rate of patients with positive anti-HCV.

[Effects of water-nitrogen interactions on NH3 and N2O emissions and yield in winter wheat cropland]. / 水氮互作对冬小麦农田NH3和N2O排放及产量的影响.

To investigate the effects of different irrigation and nitrogen application modes on nitrogen gaseous loss in winter wheat farmland, we conducted a field experiment at Changqing Irrigation Experiment Station in Shandong Province, with two irrigation levels (80%-90% θf(I1) and 70%-80% θf(I2)) and three nitrogen application levels (conventional nitrogen application of 240 kg·hm-2(N1), nitrogen reduction of 12.5% (N2), and nitrogen reduction of 25% (N3)). The results showed that ammonia volatilization and nitrous oxide emission rate peak appeared within 2-4 days after fertilization or irrigation. The ammonia volatilization rate during the chasing fertilizer period was significantly higher than that during the basal fertilizer period. Compared with other treatments, the ave-rage ammonia volatilization rate of I2N2 treatment during the chasing fertilizer period was reduced by 10.1%-51.6%, and the average nitrous oxide emission rate over the whole growth period was reduced by 15.4%-52.2%. The ammonia volatilization rate was significantly positively associated with surface soil pH value and ammonium nitrogen content, while the nitrous oxide emission rate was significantly positively associated with nitrate content in topsoil. The accumulation amount of soil ammonia volatilization and nitrous oxide emission ranged from 0.83-1.42 and 0.11-0.33 kg·hm-2, respectively. Moderate reduction of irrigation water and nitrogen input could effectively reduce cumulative amounts of ammonia volatilization and nitrous oxide emission from winter wheat farmland. The cumulative amounts of ammonia volatilization and nitrous oxide emission under I1N3 and I2N2 treatments were signi-ficantly lower than those under other treatments. The highest winter wheat yield (5615.6 kg·hm-2) appeared in I2N2 treatment. The irrigation water utilization efficiency of I2 was significantly higher than that of I1, with the maximum increase rate of 45.2%. Compared with N1 and N3 treatments, the maximum increase rate of nitrogen fertilizer productivity and agricultural utilization efficiency in N2 reached 15.2% and 31.8%, respectively. In conclusion, the treatment with 70%-80% θf irrigation level and 210 kg·hm-2 nitrogen input could effectively improve the utilization efficiency of irrigation water and nitrogen fertilization and reduce gaseous loss from winter wheat farmland.

Cuprous oxide-demethyleneberberine nanospheres for single near-infrared light-triggered photoresponsive-enhanced enzymatic synergistic antibacterial therapy.

In this work, novel cuprous oxide-demethyleneberberine (Cu2O-DMB) nanomaterials are successfully synthesized for photoresponsive-enhanced enzymatic synergistic antibacterial therapy under near-infrared (NIR) irradiation (808 nm). Cu2O-DMB has a spherical morphology with a smaller nanosize and positive ζ potential, can trap bacteria through electrostatic interactions resulting in a targeting function. Cu2O-DMB nanospheres show both oxidase-like and peroxidase-like activities, and serve as a self-cascade platform, which can deplete high concentrations of GSH to produce O2˙- and H2O2, then H2O2 is transformed into ˙OH, without introducing exogenous H2O2. At the same time, Cu2O-DMB nanospheres become photoresponsive, producing 1O2 and having an efficient photothermal conversion effect upon NIR irradiation. The proposed mechanism is that the generated ROS (O2˙-, ˙OH and 1O2) and hyperthermia can have synergetic effects for killing bacteria. Moreover, hyperthermia is not only beneficial for destroying bacteria, but also effectively enhances the efficiency of ˙OH production and accelerates GSH oxidation. Upon NIR irradiation, Cu2O-DMB nanospheres exhibit excellent antibacterial ability against methicillin-resistant Staphylococcus aureus (MRSA) and ampicillin-resistant Escherichia coli (AREC) with low cytotoxicity and bare bacterial resistance, destroy the bacterial membrane causing an efflux of proteins and disrupt the bacterial biofilm formation. Animal experiments show that the Cu2O-DMB + NIR group can efficiently treat MRSA infection and promote wound healing. These results suggest that Cu2O-DMB nanospheres are effective materials for combating bacterial infections highly efficiently and to aid the development of photoresponsive enzymatic synergistic antibacterial therapy.

[Spectroscopic studies of guanidine hydrochloride-induced unfolding of hemoglobin].

In the present paper, based on the ultraviolet-visible (UV-Vis) absorption spectroscopy, fluorescence spectroscopy, and stopped flow-fluorescence spectroscopy, the authors studied the protein unfolding process of hemoglobin induced by GdmHcl. The experiments result shows that there were two different procedures about GdmHcl inducing hemoglobin unfolding from the evidences of UV-Vis absorption spectrum and fluorescence phase diagrams. Namely, the hemoglobin subunit exhibits depolymerization, forming the intermediates when incubated with GdmHcl at the concentration of 1. 0 mol x L(-1). With the increase in the concentration, various subunit structure became loose gradually, and the protoheme collapsed eventually. UV-Vis absorption spectroscopy indicates that the addition of reductant can cooperate with the depolymerization of hemoglobin subunit and the disaggregation of protoheme. The reductant results in the unfolding procedure that hemoglobin from "three-state model" turns into "two-state model".