Combined DFT and kinetic Monte Carlo study of a bridging-spillover mechanism on fluorine-decorated graphene.

In this work, combining first-principles calculations with kinetic Monte Carlo (KMC) simulations, we constructed an irregular carbon bridge on the graphene surface and explored the process of H migration from the Pt catalyst to carbon bridge, and further migration to the graphene surface. The calculated reaction diagrams show that the hydrogen atoms can easily migrate from the Pt cluster to the carbon bridge with a low barrier of 0.22-0.86 eV, and KMC simulations indicate that the migration reactions can take place at intermediate temperatures (91.9-329.5 K). Our research clarified the role of the carbon bridge: (1) the close combination of Pt clusters and carbon bridges reduces H2 adsorption enthalpy, which facilitates the spillover of H atoms from the Pt cluster to the carbon bridges and (2) the unsaturated carbon atoms on the carbon bridges have radical character and tend to bind radical H atoms. The subsequent study shows that the F atoms decorated on graphene can greatly reduce the migration barrier of H atoms from the carbon bridge to graphene. With F atoms decorated, the carbon atoms are in an electron-deficient state, which have a strong ability to bind the hydrogen atoms, and it promotes the migration of H atoms to the graphene surface. The migration barrier and reaction temperature are reduced to 0.72 eV and 279 K, respectively.

"On Water" Direct Organocatalytic Cyanoarylmethylation of Isatins for the Diastereoselective Synthesis of 3-Hydroxy-3-cyanomethyl Oxindoles.

An "on water" organocatalytic cyanoarylmethylation of aryl acetonitrile to isatins is developed, giving products in high yields and up to excellent diastereoselectivities. A remarkable enhancement of reaction rates and diastereoselectivities by water was observed under mild conditions. Moreover, this approach provides a highly efficient and environmentally benign access to thermodynamic 3-hydroxy-3-cyanomethyl oxindoles.

Transcranial Doppler Ultrasonography detection on cerebral infarction and blood vessels to evaluate hypoxic ischemic encephalopathy modeling.

BACKGROUND: This study aimed to observe changes of rats' brain infarction and blood vessels during neonatal hypoxic ischemic encephalopathy (NHIE) modeling by Transcranial Doppler Ultrasonography (TCD) so as to assess the feasibility of TCD in evaluating NHIE modeling. METHODS: Postnatal 7-days (d)-old Sprague Dawley (SD) rats were divided into the Sham group, hypoxic-ischemic (HI) group, and hypoxia (H) group. Rats in the HI group and H group were subjected to hypoxia-1 hour (h), 1.5 h and 2.5 h, respectively. Evaluation on brain lesion was made based on Zea-Longa scores, hematoxylin-eosin (HE) staining and Nissl staining. The brain infarction and blood vessels of rats were monitored and analyzed under TCD. Correlation analysis was applied to reveal the connection between hypoxic duration and infarct size detected by TCD or Nissl staining. RESULTS: In H and HI modeling, longer duration of hypoxia was associated with higher Zea-Longa scores and more severe nerve damage. On the 1 d after modeling, necrosis was found in SD rats' brain indicated by HE and Nissl staining, which was aggravated as hypoxic duration prolonged. Alteration of brain structures and blood vessels of SD rats was displayed in Sham, HI and H rats under TCD. TCD images for coronal section revealed that brain infarct was detected at the cortex and there was marked cerebrovascular back-flow of HI rats regardless of hypoxic duration. On the 7 d after modeling, similar infarct was detected under TCD at the cortex of HI rats in hypoxia-1 h, 1.5 h and 2.5 h groups, whereas the morphological changes were deteriorated with longer hypoxic time. Correlation analysis revealed positive correlation of hypoxic duration with infarct size detected by histological detection and TCD. CONCLUSIONS: TCD dynamically monitored cerebral infarction after NHIE modeling, which will be potentially served as a useful auxiliary method for future animal experimental modeling evaluation in the case of less animal sacrifice.

Ultrasound-guided puncture into newborn rat brain.

Since the brain structure of neonatal rats was not fully formed during the first 4 days, it cannot be detected using ultrasound. The objective of this study was to investigate the use of ultrasound to guide puncture in the normal coronal brain structure and determine the puncture depth of the location of the cortex, hippocampus, lateral ventricle, and striatum of newborn rats of 5-15 days. The animal was placed in a prone position. The specific positions of the cortex, hippocampus, lateral ventricle, and striatum were measured under ultrasound. Then, the rats were punctured with a stereotaxic instrument, and dye was injected. Finally, the brains of rats were taken to make frozen sections to observe the puncture results. By ultrasound, the image of the cortex, hippocampus, lateral ventricle, and striatum of the rat can be obtained and the puncture depth of the cortex (8 days: 1.02 ± 0.12, 10 days: 1.02 ± 0.08, 13 days: 1.43 ± 0.05), hippocampus (8 days: 2.63 ± 0.07, 10 days: 2.77 ± 0.14, 13 days: 2.82 ± 0.09), lateral ventricle (8 days: 2.08 ± 0.04, 10 days: 2.26 ± 0.03, 13 days: 2.40 ± 0.06), and corpus striatum (8 days: 4.57 ± 0.09, 10 days: 4.94 ± 0.31, 13 days: 5.13 ± 0.10) can be accurately measured. The rat brain structure and puncture depth changed with the age of the rats. Ultrasound technology can not only clarify the brain structure characteristics of 5-15-day-old rats but also guide the puncture and injection of the rat brain structure. The results of this study laid the foundation for the future use of ultrasound in experimental animal models of neurological diseases.

Transcranial Doppler Ultrasonography detection on cerebrovascular flow for evaluating neonatal hypoxic-ischemic encephalopathy modeling.

Objective: This study aimed to investigate the feasibility of Transcranial Doppler Ultrasonography (TCD) in evaluating neonatal hypoxic-ischemic encephalopathy (NHIE) modeling through monitoring the alteration of cerebrovascular flow in neonatal hypoxic-ischemic (HI) rats. Methods: Postnatal 7-day-old Sprague Dawley (SD) rats were divided into the control group, HI group, and hypoxia (H) group. TCD was applied to assess the changes of cerebral blood vessels, cerebrovascular flow velocity, and heart rate (HR) in sagittal and coronal sections at 1, 2, 3, and 7 days after the operation. For accuracy, cerebral infarct of rats was examined by 2,3,5-Triphenyl tetrazolium chloride (TTC) staining and Nissl staining to simultaneously verify the establishment of NHIE modeling. Results: Coronal and sagittal TCD scans revealed obvious alteration of cerebrovascular flow in main cerebral vessels. Obvious cerebrovascular back-flow was observed in anterior cerebral artery (ACA), basilar artery (BA), middle cerebral artery (MCA) of HI rats, along with accelerated cerebrovascular flows in the left internal carotid artery (ICA-L) and BA, decreased flows in right internal carotid artery (ICA-R) relative to those in the H and control groups. The alterations of cerebral blood flows in neonatal HI rats indicated successful ligation of right common carotid artery. Besides, TTC staining further validated the cerebral infarct was indeed caused due to ligation-induced insufficient blood supply. Damage to nervous tissues was also revealed by Nissl staining. Conclusion: Cerebral blood flow assessment by TCD in neonatal HI rats contributed to cerebrovascular abnormalities observed in a real-time and non-invasive way. The present study elicits the potentials to utilize TCD as an effective means for monitoring the progression of injury as well as NHIE modeling. The abnormal appearance of cerebral blood flow is also beneficial to the early warning and effective detection in clinical practice.

A case report of the treatment and care of decubitus ulcers in macaques with spinal cord injury.

Decubitus ulcers are a common spinal cord injury (SCI) complication that puts patients' lives in danger and has emerged as a more prevalent issue in modern clinical rehabilitation and care. Decubitus ulcers in humans can currently be treated in a number of different ways, but there are fewer studies on how to treat and care for decubitus ulcers in macaques. To treat a 20-year-old adult male macaque monkey with SCI and decubitus ulcers after a quarter transection of the thoracic spinal cord, a number of scientific care procedures and pharmaceutical treatments, such as dietary changes and topical or intravenous administration of medication, were carried out and continuously monitored in real-time. In comparison to the untreated group, we observed a significant improvement in decubitus wound healing in the macaques. In this article, we provide a good protocol for decubitus ulcer care after SCI and suggest that future experimental animal modeling needs to focus on issues such as care for postoperative complications.

Development of an innovative minimally invasive primate spinal cord injury model: A case report.

Spinal cord injury (SCI) animal models have been widely created and utilized for repair therapy research, but more suitable experimental animals and accurate modeling methodologies are required to achieve the desired results. In this experiment, we constructed an innovative dorsal 1/4 spinal cord transection macaque model that had fewer severe problems, facilitating postoperative care and recovery. In essence, given that monkeys and humans share similar genetics and physiology, the efficacy of this strategy in a nonhuman primate SCI model basically serves as a good basis for its prospective therapeutic use in human SCI.

Anisodamine hydrobromide in the treatment of critically ill patients with septic shock: a multicenter randomized controlled trial.

BACKGROUND: Septic shock is the development of sepsis to refractory circulatory collapse and metabolic derangements, characterized by persistent hypotension and increased lactate levels. Anisodamine hydrobromide (Ani HBr) is a Chinese medicine used to improve blood flow in circulatory disorders. The purpose of this study was to determine the therapeutic efficacy of Ani HBr in the treatment of patients with septic shock. METHODS: This was a prospective, multicenter, randomized controlled trial focusing on patients with septic shock in 16 hospitals in China. Patients were randomly assigned in a 1:1 ratio to either the treatment group or the control group. The primary endpoint was 28-day mortality. The secondary outcomes included 7-day mortality, hospital mortality, hospital length of stay, vasopressor-free days within 7 days, etc. These indicators were measured and collected at 0, 6h, 24h, 48h, 72h and 7d after the diagnosis. RESULTS: Between September 2017 and March 2021, 404 subjects were enrolled. 203 subjects received Ani HBr and 201 subjects were assigned to the control group. The treated group showed lower 28-day mortality than the control group. Stratified analysis further showed significant differences in 28-day mortality between the two groups for patients with a high level of illness severity. We also observed significant differences in 7-day mortality, hospital mortality and some other clinical indicators between the two groups. CONCLUSION: Ani HBr might be an important adjuvant to conventional treatment to reduce 28-day mortality in patients with septic shock. A large-scale prospective randomized multicenter trial is warranted to confirm our results.

Normal cerebral blood vessels under ultrasound in SD rats of different ages.

The objective of this study was to examine whether ultrasound can examine the development of cerebral vascular structure and cerebral blood flow in Sprague-Dawley (SD) rats by ultrasound in a noninvasive manner, which provides a reference for ultrasound research of SD rats. Thirty-nine SD rats (7-16 days old) were divided into seven groups according to age, and the number of SD rats in each group was, respectively, 7, 17, 1, 3, 2, 8, and 1. Ultrasound was used to detect cerebral blood vessels, cerebrovascular flow velocity, and heart rate in SD rats in the sagittal and coronal positions, and images were obtained in B-mode ultrasound. The cerebral vascular structure of 39 SD rats (7-16 days) was dynamically observed under B-ultrasound. We found that the cerebral vascular structure of the rats aged 7-10 days was clear and detectable. Rats aged 11-16 days of cerebral vascular structures became thinner and undetectable. Quantitative analysis of cerebrovascular flow rate and heart rate in rats found that there was no significant difference in cerebrovascular blood flow rate and heart rate between 7 and 8 days. Ultrasound can also be used in rat animal studies, that is, the cerebral blood flow in rats of different ages can be monitored in real-time by ultrasound in a noninvasive way.

Nuances of Whitefly Vector-Crinivirus Interactions Revealed in the Foregut Retention and Transmission of Lettuce Chlorosis Virus by Two Bemisia tabaci Cryptic Species.

Lettuce infectious yellows virus is the first crinivirus for which the retention of purified virions ingested into the whitefly (Bemisia tabaci New World (NW)) vector's foregut, has been demonstrated to be a requisite for successful virus transmission. This key finding supports the hypothesis that the determinant of foregut retention and transmission is present on the virion itself. However, whether this is also true for other criniviruses has not been established. Here, we provide evidence that lettuce chlorosis virus (LCV) acquired from plants is retained in the foreguts of both the B. tabaci NW and Middle East-Asia Minor 1 (MEAM1) vector species and transmitted upon inoculation feeding. An association between foregut retention and transmission by NW vectors is also observed following the acquisition and inoculation feeding of LCV virions purified using a standard procedure involving 2% or 4% (v/v) Triton™ X-100 (TX-100). However, while virions purified with 2% or 4% TX-100 are also retained in the foreguts of MEAM1 vectors, transmission is observed with the 4% TX-100-purified virions or when more vectors are used for acquisition and inoculation feeding. These results suggest that an intrinsic difference exists between NW and MEAM1 vectors in their interactions with, and transmission of, LCV virions.

Salt tolerance of a wild ecotype of vetiver grass (Vetiveria zizanioides L.) in southern China.

BACKGROUND: Vetiver grass (Vetiveria zizanioides L.) is widely used in more than 120 countries for land management (e.g. rehabilitation of saline lands). A wild ecotype of vetiver grass was found in southern China in the 1950s, but little is known about its adaptability to saline stress. For the purpose of understanding its tolerance to salinity as well as corresponding tolerance mechanisms, in a greenhouse with natural lighting, seedlings were grown in culture solutions and subjected to a range of NaCl concentrations for 18 days. RESULTS: Compared to no NaCl treatment, 200 mM NaCl significantly reduced leaf water potential, leaf water content, leaf elongation rate, leaf photosynthetic rate and plant relative growth rate and increased leaf malondialdehyde (MDA) content, but the parameters showed only slight reduction at 150 mM NaCl. In addition, salinity caused an increase in the activity of antioxidant enzymes in leaves. Moreover, increasing NaCl levels significantly increased Na+ but decreased K+ concentrations in both roots and leaves. The leaves had higher K+ concentrations at all NaCl levels, but lower Na+ concentrations compared to the roots, thereby maintaining higher K+/Na+ ratio in leaves. CONCLUSIONS: Our results showed that the salinity threshold of this wild vetiver grass is about 100 mM NaCl, i.e. highly tolerant to salt stress. This wild vetiver grass has a high ability to exclude Na+ and retain K+ in its leaves, which is a critical strategy for salt tolerance.

Clinical utility of the ventricular septal defect diameter to aorta root diameter ratio to predict early childhood developmental defects or lung infections in patients with perimembranous ventricular septal defect.

BACKGROUND: Ventricular septal defect (VSD) is the most frequent type of congenital heart disease. Conventional methods to evaluate VSD size and severity are both invasive and cumbersome to perform. We investigated whether the ratio between the diameter of the defect and the aortic root diameter (DVSD/DAR) would accurately reflect the degree of shunted blood and the severity of VSD in children with perimembranous VSD. METHODS: We recruited 987 children with perimembranous VSD (pmVSD) and used color Doppler echocardiography to calculate DVSD/DAR. 987 healthy children were recruited as control group. The pmVSD group was further stratified into four groups according to age (1 to 4 y) and again into four groups according to the DVSD/DAR ratio: children whose DVSD/DAR was 1/5 to <1/4, 1/4 to <1/3, 1/3 to 1/5, or 1/2 to <2/3 were assigned to groups A, B, C, and D, respectively. Height, weight, infection scores and systemic-pulmonary circulation ratio (QP/QS ratio) were compared among groups A, B, C and D. Then the relationship between the DVSD/DAR ratio and height, weight, QP/QS ratio, infection score were analysed by linear regression analysis. RESULTS: Compared to age-matched children without VSD (the controls), the mean height and weight of children in the pmVSD group were lower, and heights and weights were negatively correlated with the DVSD/DAR ratio. This ratio was significantly reduced in groups C and D compared to control group (both P<0.05). Infection scores of groups A and B were significantly higher only in the one-year-old subgroup, but were significantly higher in groups C and D for all ages compared to the control group (both P<0.05). QP/QS ratio of group C and D were higher than group A and group B (all P<0.05). Moreover, QP/QS ratio of group D for all ages were more than 2. In addition, linear regression analysis revealed that the DVSD/DAR ratio negatively correlated with height and weight and positively correlated with the QP/QS ratio and infection score. CONCLUSIONS: Our results suggest that the DVSD/DAR ratio accurately reflects the growth and pulmonary infection rates in children with pmVSD. This ratio, therefore, may be a useful additional reference index to predict the consequences of pmVSD.

Emodin induces Panc-1 cell apoptosis via declining the mitochondrial membrane potential.

In this study, we investigated the apoptotic effect of emodin on human pancreatic cancer cell line Panc-1 in vitro and in vivo as well as the possible mechanisms involved. In vitro, human pancreatic cancer cell line Panc-1 was exposed to varying concentrations of emodin (0, 10, 20, 40 or 80 µmol/l). Then the mitochondrial membrane potential (MMP) was analyzed by JC-1 staining, cell apoptosis was analyzed by flow cytometry (FCM) and cell proliferation was analyzed by MTT. In vivo, nude mice orthotopically implanted were randomly divided into five groups to receive treatments by different doses of emodin: control group (normal saline 0.2 ml), E10 group (emodin 10 mg/kg), E20 group (emodin 20 mg/kg), E40 group (emodin 40 mg/kg) and E80 group (emodin 80 mg/kg). Each mouse was treated 5 times by intraperitoneal injection of emodin every 3 days. During the treatment, the feeding stuff was recorded. One week after the last treatment, we recorded the body weight and the maximum diameter of tumor in each group before the mice were sacrificed. Then the cell apoptosis of the tumor was tested by TUNEL assay. The results in vitro showed that the MMP of the cells declined and the apoptosis rate increased with the emodin concentration increasing and the cell proliferation of each group was inhibited in a dose- and time-dependent manner by emodin. The feeding stuff curve did not decline significantly in E40 group and the apoptosis rate of the tumor cells in this group was higher than the lower-dose groups. Taken together, our results demonstrate that emodin may induce the pancreatic cancer cell apoptosis via declining the MMP and a moderate dose of emodin improved the living state of the model mice.

Enhanced antitumor efficacy by the combination of emodin and gemcitabine against human pancreatic cancer cells via downregulation of the expression of XIAP in vitro and in vivo.

XIAP and NF-κB play an important role in chemotherapy resistance in pancreatic cancer. The purpose of this study was to explore the role of XIAP and NF-κB in potentiating the antitumor effect of gemcitabine by emodin in pancreatic cancer. SW1990 cells were treated by sodium chloride, gemcitabine, emodin or their combination (gemcitabine plus emodin). Cellular proliferation and apoptosis were detected by Cell Counting kit-8 (CCK-8) assay and flow cytometry in vitro. The combination therapy more significantly inhibited SW1990 cell growth and induced a higher percentage of apoptosis than monotherapy. Gemcitabine upregulated the expression of XIAP and NF-κB, while emodin or emodin plus gemcitabine downregulated them compared to the control group in vitro. SW1990 cells were used to establish orthotopic pancreatic tumor models in nude mice. Tumor-bearing mice were treated with sodium chloride, emodin, gemcitabine or their combination. After being treated for 4 weeks, the nude mice were imaged with high-resolution positron emission tomography (microPET) and fluorine-18-labeled fluorodeoxyglucose (18F-FDG) to detect the tumor/non-tumor ratio (T/NT ratio) and standard uptake value (SUV). The mice were sacrificed to determine tumor weight. The combination of emodin and gemcitabine showed more significant reduction in the T/NT ratio, SUV and tumor weight compared to monotherapy. The mRNA levels and the protein expression of XIAP and NF-κB were upregulated in the gemcitabine group, while they were downregulated in the emodin group and the combination group in vivo. Ki-67 prolif-eration index and TUNEL assay results also showed that emodin enhanced tumor apoptosis induced by gemcitabine in vivo. This study suggests that emodin enhances the antitumor effect of gemcitabine in SW1990 pancreatic cancer in vitro and in vivo, which may be via the downregulation of NF-κB expression, thus inhibiting the expression of XIAP.

[Using real-time polymerase chain reaction to quantitate bcr-abl mRNA].

BACKGROUND & OBJECTIVE: When leukemia patients achieve complete remission after chemotherapy, a few tumor cells still exist in other tissues outside bone marrow, which is called minimal residual disease (MRD), and it is the base of relapse. To cure leukemia, we should not only find MRD in time, but also quantitate MRD for instructing treatment and predicting prognosis. This study was to establish a real-time reverse transcription-polymerase chain reaction (RT-PCR) system to quantitate bcr-abl mRNA. METHODS: bcr-abl mRNA in leukemia cell line K562 was amplified by RT-PCR. T-A clone was used to construct the combined plasmid to be standard template; the standard curve of bcr-abl oncogene was drawn. bcr-abl mRNA in bone marrow samples of 16 chronic myelocytic leukemia (CML) patients was quantitated by this method. The sensitivity, stability, and repetition of this method were evaluated. RESULTS: The sensitivity is 10 copies of the recombined plasmid. The coefficient variations (CV) of repetition and stability were 2.19% and 3.21%. The correlation (R) of the standard curve was 0.984. The median bcr-abl level of the 16 CML patients was 4.58x10(4) kb/microg RNA. CONCLUSIONS: Real-time PCR has high sensitivity, repetition, and specificity. It can quantitate the copy number of bcr-abl oncogene.

[Regulative effect of electroacupuncture of different frequencies on derangement of gastric electric rhythm in rabbits].

OBJECTIVE: To investigate regulative effect of electroacupuncture (EA) of different frequencies on derangement of gastric electric rhythm in rabbits. METHODS: Derangement of gastric electric rhythm model was made with injection of erythromycin into ear vein in 40 rabbits, and randomly divided into a model group, a 3 Hz-EA group, a 20 Hz-EA group and a 100 Hz-EA group. They were treated with EA at Zusanli (ST 36) with 3 Hz, 20 Hz and 100 Hz, respectively. PDP and PTP at different periods were detected with IEGG spectrum analyzer. RESULTS: Erythromycin could significantly enhance PDP and PTP values in the rabbit (P < 0.001). PDP and PTP values were reduced significantly after EA with 3 Hz, 20 Hz and 100 Hz (P < 0.05), with no significant differences in effect on PDP among them (P > 0.05); therapeutic effect of the EA of 20 Hz on PTP was better than that of 3 Hz (P < 0.05), with no significant difference as compared with the EA of 100 Hz. CONCLUSION: EA of the 3 frequencies shows significantly different regulative effects on derangement of gastric electric rhythm in rabbits.