Subsurface hydrological connectivity controls nitrate export flux in a hilly catchment

Subsurface runoff represents the main pathway of nitrate transport in hilly catchments. The magnitude of nitrate export from a source area is closely related to subsurface hydrological connectivity, which refers to the linkage of separate regions of a catchment via subsurface runoff. However, understanding of how subsurface hydrological connectivity regulates catchment nitrate export remains insufficient. This study conducted high-frequency monitoring of shallow groundwater in a hilly catchment over 17 months. Subsurface hydrological connectivity of the catchment over 38 rainfall events was analyzed by combining topography-based upscaling of shallow groundwater and graph theory. Moreover, cross-correlation analysis was used to evaluate the time-series similarity between subsurface hydrological connectivity and nitrate flux during rainfall events. The results showed that the maximum subsurface hydrological connectivity during 32 out of 38 rainfall events was below 0.5. Although subsurface flow paths (i.e., the pathways of lateral subsurface runoff) exhibited clear dynamic extension and contraction during rainfall events, most areas in the catchment did not establish subsurface hydrological connectivity with the stream. The primary pattern of nitrate export was flushing (44.7%), followed by dilution (34.2%), and chemostatic behavior (21.1%). A threshold relationship between subsurface hydrological connectivity and nitrate flux was identified, with nitrate flux rapidly increasing after the subsurface connectivity strength exceeded 0.121. Moreover, the median value of cross-correlation coefficients reached 0.67, which indicated subsurface hydrological connectivity exerts a strong control on nitrate flux. However, this control effect is not constant and it increases with rainfall amount and intensity as a power function. The results of this study provide comprehensive insights into the subsurface hydrological control of catchment nitrate export.

The performance of a new type accelerator uRT-linac 506c evaluated by a quality assurance automation system

PURPOSE

The purpose of this study was to evaluate the performance of our quality assurance (QA) automation system and to evaluate the machine performance of a new type linear accelerator uRT-linac 506c within 6 months using this system.

METHODS

This QA automation system consists of a hollow cylindrical phantom with 18 steel balls in the phantom surface and an analysis software to process electronic portal imaging device (EPID) measurement image data and report the results. The performance of the QA automation system was evaluated by the tests of repeatability, archivable precision, detectability of introduced errors, and the impact of set-up errors on QA results. The performance of this linac was evaluated by 31 items using this QA system over 6 months.

RESULTS

This QA system was able to automatically deliver QA plan, EPID image acquisition, and automatic analysis. All images acquiring and analysis took approximately 4.6 min per energy. The preset error of 0.1 mm in multi-leaf collimator (MLC) leaf were detected as 0.12 ± 0.01 mm for Bank A and 0.10 ± 0.01 mm in Bank B. The 2 mm setup error was detected as -1.95 ± 0.01 mm, -2.02 ± 0.01 mm, 2.01 ± 0.01 mm for X, Y, Z directions, respectively. And data from the tests of repeatability and detectability of introduced errors showed the standard deviation were all within 0.1 mm and 0.1°. and data of the machine performance were all within the tolerance specified by AAPM TG-142.

CONCLUSIONS

The QA automation system has high precision and good performance, and it can improve the QA efficiency. The performance of the new accelerator has also performed very well during the testing period.

[Preliminary insights into the practice of hypoallergenic home visiting program]

Allergic diseases affect about 40% of the world's population. Environmental factors are important in the occurrence and development of allergic diseases. Dust mites are one of the most important allergens in the indoor environment. The World Health Organization proposes the "four-in-one, combination of prevention and treatment" treatment principle for allergic diseases, in which environmental control to avoid or reduce allergens is the first choice for treatment. Modern people spend much more time at home (including sleeping) than outdoors, and the control of the home environment is particularly critical. This practice introduces the hypoallergenic home visit program, which including home environment assessment, environmental and behavioral intervention guidance, and common household hypoallergenic supplies and service guidance for the patient's home environment. The real-time semi-quantitative testing of dust mite allergens, qualitative assessments of other indoor allergens, record of patients' household items and lifestyle, and precise, individualized patient prevention and control education will be conducted. The hypoallergenic home visit program improves the doctors' diagnosis and treatment data dimension, and becomes a patient management tool for doctors outside the hospital. It also helps patients continue to scientifically avoid allergens and irritants in the environment, effectively build a hypoallergenic home environment, reduce exposure to allergens in the home environment, and achieve the goal of combining the prevention and treatment of allergic diseases.

Assessing hydrological connectivity for natural-artificial catchment with a new framework integrating graph theory and network analysis

Anthropogenic activities alter the underlying surface conditions and arrangements of landscape features in a drainage basin, interfering with the pollutant (e.g., dissolved nitrogen, phosphorus) transport network configuration and altering the hydrological response. Assessing the impact of anthropogenic activities on hydrological connectivity for natural-artificial catchment is critical to understand the hydrological-driven ecosystem processes, services and biodiversity. However, quantifying this impact at catchment scale remains challenging. In this study, a new framework was proposed to quantify the impact of anthropogenic activities on hydrological connectivity combined with graph theory and network analysis. This framework was exemplified in a natural-artificial catchment of the Yangtze River basin of China. Based on remote sensing and field-investigated data, three transport networks were constructed, including natural transport network (N1), ditch-road transport network (N2), and terrace-dominated transport network (N3), which reflected the different human intervention. The results showed that human intervention improved the connectivity of the nodes and enhanced the complexity of the catchment transport network structure. Anthropogenic activities significantly decreased the hydrological structural connectivity of the catchment. In particular, compared with the N1 network, the critical nodes for hydrological connectivity which were judged by connectivity indexes were reduced by 92.94% and 95.29% in the N2 and N3 network, respectively. Furthermore, the ditch-road construction had a greater impact than terraces in decreasing hydrological structural connectivity at catchment scale. This framework has proven effective in quantifying the hydrological connectivity analysis under different human intervention at the catchment scale and facilitates the improvement of catchment management strategies.

[Diagnosis and treatment procedures and health management for patients with hereditary angioedema]

As a recognized rare and highly fatal disease, hereditary angioedema (HAE) is difficult to diagnose and characterized by recurrent edema involving the head, limbs, genitals and larynx, etc. Diagnosis of HAE is not difficult. However, low incidence and lack of clinical characteristics lead to difficulty of doctors on timely diagnosis and correct intervention for HAE patients. Therefore, it is crucial to improve the awareness of this disease and prevent its recurrence. for HAE patients. In view of absent cognition of doctors and the general public on HAE, patients often suffer from sudden death or become disabled due to laryngeal edema which cannot be treated in time. Thus, based on the Internet mobile terminal platform, the team set up an all-day rapid emergency response system which is provided for HAE patients by setting up "one-click help". The aim is to offer optimization on overall management of HAE and designed the intelligent follow-up management to provide timely assistance and specialized suggestion for patients with acute attacks.

Hysteresis analysis reveals dissolved carbon concentration - discharge relationships during and between storm events

The dissolved carbon concentration, which is responsible for aquatic ecosystem productivity and water quality, is tightly coupled with hydrological processes. Excess dissolved carbon may exacerbate eutrophication and hypoxia in aquatic ecosystems and lead to deterioration of water quality. Storm events dominate the dynamics of dissolved carbon concentrations, and this nonlinear behavior exhibits significant time scale dependence. Here, we identified inter- and intra-event variability in the dissolved carbon concentration-discharge (C-Q) relationship in an agriculture-intensive catchment. The driving factors of C-Q hysteresis patterns for dissolved inorganic carbon (DIC) and organic carbon (DOC) were quantified by redundancy analysis combined with hierarchical partitioning. At the inter-event scale, DIC exhibited mainly clockwise hysteresis, indicating an exhaustible, proximal source (e.g., groundwater). However, DOC hysteresis was generally counter-clockwise, indicating distal and plentiful sources (e.g., soil water) in the agricultural catchment. Hierarchical partitioning showed that total rainfall, peak discharge and flood intensity explained 28.38% of the total variation in C-Q hysteresis for DIC and 39.87% for DOC at the inter-event scale. At the intra-event scale, time series analysis of dissolved carbon concentration and discharge indicated the interconversion of supply limitation to transport limitation, which depends on the activation of the specific DIC or DOC source zones. These findings provide significant insights into understanding the dynamics of dissolved carbon during storm periods and are important for targeted watershed management practices aimed at reducing carbon loading to surface waters.

High-frequency monitoring of neonicotinoids dynamics in soil-water systems during hydrological processes

Neonicotinoids pollution poses a serious threat to aquatic ecosystems. However, there is currently little knowledge about how neonicotinoids are transferred from the agricultural environment to the aquatic environment. Here, we conducted in situ high-frequency monitoring of neonicotinoids in soil-water systems along the hydrological flow path during rainfall to explore the horizontal and vertical transport mechanisms of neonicotinoids. The collected samples included 240 surface runoff, 128 subsurface runoff, 60 eroded sediment, 120 soil and 144 soil solution, which were used to analyse neonicotinoids concentrations. Surface runoff, subsurface runoff and eroded sediment were the three main paths for the horizontal migration of neonicotinoids. In the CK (citrus orchards without grass cover) and grass-covered citrus orchards, there are 15.89% and 2.29% of the applied neonicotinoids were transported with surface runoff, respectively. While in the CK and grass-covered citrus orchards, there are only 1.23% and 0.19% of the applied neonicotinoids were transported with eroded sediment and subsurface runoff. Although the amount of neonicotinoids lost along with eroded sediment was small, the concentration of neonicotinoids in eroded sediment was two orders of magnitude higher than the concentration of neonicotinoids in sediments of the surface water. Meanwhile, neonicotinoids migrated vertically in soil due to water infiltration. In the CK and grass-covered citrus orchards, there are 57.64% and 24.36% of the applied neonicotinoids were retained in soil and soil solution, respectively, and their concentration decreased as soil depth increased. Another noteworthy phenomenon is that more neonicotinoids migrated to deeper soil layers under grass cover compared with no grass cover because grass roots promoted the formation of cracks and vertical preferential flow. Our results are expected to improve the accuracy of neonicotinoids pollution prediction by considering migration paths, including surface and subsurface runoff and eroded sediment.

[A multicenter randomized controlled study of bismuth-containing quadruple therapy followed by Jing-Hua-Wei-Kang in the treatment of patients newly diagnosed with Helicobacter pylori infection and dyspepsia]

Objective: To investigate the Helicobacter pylori (H. pylori) eradication rate and improvement of dyspepsia in patients who were newly diagnosed with H. pylori infection and dyspepsia and treated by bismuth-containing quadruple therapy followed by Jing-Hua-Wei-Kang(JHWK). Methods: Patients who were newly diagnosed with dyspepsia and H. pylori infection and treated in 16 medical centers in China between December 1, 2017 and September 30, 2019 were randomly divided into two groups. The experimental group received bismuth-containing quadruple therapy (esomeprazole+amoxicillin+furazolidone+colloidal bismuth pectin capsule, 14 days), followed by JHWK (30 days), and the course of treatment was 44 days in total. In the control group, the administration regimen was bismuth-containing quadruple therapy (esomeprazole+amoxicillin+furazolidone+colloidal bismuth pectin capsule, 14 days). The main outcome measure was H. pylori eradication rate, while the secondary outcome measures were dyspepsia symptom changes and adverse events during the treatment and the 1st month after treatment. Results: A total of 1 054 patients were included in the study. There were 522 cases enrolled in the experimental group, including 224(42.91%) men and 298(57.09%) women, and the age was 53(26, 73) years old; 532 cases enrolled in the control group, including 221(41.54%) men and 311(58.46%) women, and the age was 46(22, 71) years old. Based on PP analysis, it was found that the H. pylori eradication rate in the experimental group was significantly higher than those in the control group (93.85% vs 87.88%, P=0.001). In the group of all enrolled patients, the symptom dyspepsia after H. pylori eradication was significantly improved compared with that before treatment [4(4, 7) vs 15(10, 22), P<0.001], so was the superior and middle abdominal pain [1(1, 4) vs 4(1, 8), P<0.001], the postprandial fullness [1(1, 4) vs 4(4, 9), P<0.001], the early satiety [1(1, 1) vs 4(1, 4), P<0.001], and the heartburn [1(1, 1) vs 1(1, 4), P<0.001]. The symptom dyspepsia after treatment was significantly improved compared with that before treatment in the experimental, the control groups, the successful and the unsuccessful H. pylori eradication groups. The superior and middle abdominal pain after treatment was signifcantly improved than that before treatment [1(1, 2) vs 1(1, 4), P<0.001], so were the postprandial fullness [1(1, 3) vs 1(1, 4), P=0.002] and the dyspepsia[4(4, 7) VS 7(4, 10), P<0.001]. There was no statistically significant difference in the incidence of adverse events between the experimental group and the control group (1.34% vs 0.38%, P=0.09). Conclusions: Compared with bismuth-containing quadruple therapy, bismuth-containing quadruple therapy followed by JHWK significantly improves the H. pylori eradication rate without increasing the incidence of adverse events. H. pylori eradication therapy can improve symptoms of patients with H. pylori infection and dyspepsia.

Role of a successful spontaneous breathing trial in ventilator liberation in brain-injured patients

BACKGROUND

Spontaneous breathing trials (SBTs) have been shown to improve outcomes in critically ill patients. However, in patients with brain injury, indications for intubation and mechanical ventilation are different from those of non-neurological patients, and the role of an SBT in patients with brain injury is less established. The aim of the present study was to compare key respiratory variables acquired during a successful SBT between patients with successful ventilator liberation versus failed ventilator liberation.

METHODS

In this prospective study, patients with brain injury (≥18 years of age), who completed a 30-min SBT, were enrolled. Airway pressure, flow, esophageal pressure, and diaphragm electrical activity (ΔEAdi) were recorded before (baseline) and during the SBT. Respiratory rate (RR), tidal volume, inspiratory muscle pressure (ΔPmus), ΔEAdi, and neuromechanical efficiency (ΔPmus/ΔEAdi) of the diaphragm were calculated breath by breath and compared between the liberation success and failure groups. Failed liberation was defined as the need for invasive ventilator assistance within 48 h after the SBT.

RESULTS

In total, 46 patients (51.9±13.2 years, 67.4% male) completed the SBT. Seventeen (37%) patients failed ventilator liberation within 48 h. Another 11 patients required invasive ventilation within 7 days after completing the SBT. There were no differences in baseline characteristics between the success and failed groups. In-depth analysis showed similar changes in patterns and values of respiratory physiological parameters between the groups.

CONCLUSIONS

In patients with brain injury, ventilator liberation failure was common after successful SBT. In-depth physiological analysis during the SBT did not provide data to predict successful liberation in these patients.

TRIAL REGISTRATION

The trial was registered at ClinicalTrials.gov (No. NCT02863237).

Giant aneurysm of the bilateral vertebrobasilar junction treated by pipeline and coils: A case report and literature review

Giant aneurysm of the posterior circulation is associated with a higher risk of rupture compared with that of the anterior circulation. Furthermore, surgical clipping and interventional embolization for giant aneurysm of the posterior circulation are more difficult and complex to perform. The present study reported on the case of a 26-year-old female who exhibited a giant spherical aneurysm of the vertebrobasilar junction (VBJ) with a maximum diameter of ~35 mm that caused cervical discomfort. In addition, the patient experienced symptoms including left-sided walking and hoarseness caused by the compression of the brainstem and the posterior cranial nerves. The risks associated with performing surgery in this area are high and the prognosis is mainly poor. The patient of the present study was treated using the Pipeline Flex device with coil embolization. As a giant aneurysm of the VBJ simultaneously affects the bilateral vertebral arteries (VAs) and basilar artery, it is a unique condition and the treatment strategy must be personalized. Based on an analysis of the hemodynamic influence on the aneurysm in the present case, the Pipeline was placed through the left VA, the coils were packed through the right VA, and finally, the right VA was proximally occluded. At 7 months after embolization, the patient's modified Rankin scale score was 1 point. Upon analysis of the hemodynamic influence on the aneurysm of the VBJ, the VA with the larger shear force on the wall of the aneurysm was selected for occlusion to simplify the treatment of the aneurysm and to maximize the probability to achieve recovery.

Breath-synchronized electrical stimulation of the expiratory muscles in mechanically ventilated patients: a randomized controlled feasibility study and pooled analysis

BACKGROUND

Expiratory muscle weakness leads to difficult ventilator weaning. Maintaining their activity with functional electrical stimulation (FES) may improve outcome. We studied feasibility of breath-synchronized expiratory population muscle FES in a mixed ICU population ("Holland study") and pooled data with our previous work ("Australian study") to estimate potential clinical effects in a larger group.

METHODS

Holland: Patients with a contractile response to FES received active or sham expiratory muscle FES (30 min, twice daily, 5 days/week until weaned). Main endpoints were feasibility (e.g., patient recruitment, treatment compliance, stimulation intensity) and safety. Pooled: Data on respiratory muscle thickness and ventilation duration from the Holland and Australian studies were combined (N = 40) in order to estimate potential effect size. Plasma cytokines (day 0, 3) were analyzed to study the effects of FES on systemic inflammation.

RESULTS

Holland: A total of 272 sessions were performed (active/sham: 169/103) in 20 patients (N = active/sham: 10/10) with a total treatment compliance rate of 91.1%. No FES-related serious adverse events were reported. Pooled: On day 3, there was a between-group difference (N = active/sham: 7/12) in total abdominal expiratory muscle thickness favoring the active group [treatment difference (95% confidence interval); 2.25 (0.34, 4.16) mm, P = 0.02] but not on day 5. Plasma cytokine levels indicated that early FES did not induce systemic inflammation. Using a survival analysis approach for the total study population, median ventilation duration and ICU length of stay were 10 versus 52 (P = 0.07), and 12 versus 54 (P = 0.03) days for the active versus sham group. Median ventilation duration of patients that were successfully extubated was 8.5 [5.6-12.2] versus 10.5 [5.3-25.6] days (P = 0.60) for the active (N = 16) versus sham (N = 10) group, and median ICU length of stay was 10.5 [8.0-14.5] versus 14.0 [9.0-19.5] days (P = 0.36) for those active (N = 16) versus sham (N = 8) patients that were extubated and discharged alive from the ICU. During ICU stay, 3/20 patients died in the active group versus 8/20 in the sham group (P = 0.16).

CONCLUSION

Expiratory muscle FES is feasible in selected ICU patients and might be a promising technique within a respiratory muscle-protective ventilation strategy. The next step is to study the effects on weaning and ventilator liberation outcome.

TRIAL REGISTRATION

ClinicalTrials.gov, ID NCT03453944. Registered 05 March 2018-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03453944 .

Effect of local watershed landscapes on the nitrogen and phosphorus concentrations in the waterbodies of reservoir bays

Reservoir bays, which are affected by the reservoir and watershed characteristics, are the initial and most sensitive areas in the evolution process of reservoir water quality. However, the relationship between the watershed characteristics and nitrogen and phosphorus concentrations in reservoir bays is poorly understood. We selected 66 bays from the Danjiangkou Reservoir and sampled twice per year (storage and discharge periods) from 2015 to 2018 to monitor the total nitrogen (TN) and total phosphorus (TP) concentration in the waterbodies of the reservoir bays. Four types of watershed characteristic indices (topographic variables, soil variables, land-use composition, and landscape patterns) around these bays were obtained. We quantified the relationship between the TN and TP concentrations and watershed characteristics in the waterbodies of the reservoir bays using partial least squares regression (PLSR). The results showed that the mean concentrations of TN and TP in the storage period (TN:1.69 mg·L^-1, TP:0.088 mg·L^-1) were higher than those in the discharge period (TN:1.22 mg·L^-1, TP:0.063 mg·L^-1). The optimal PLSR models explained 67.9% and 82.5% of the TN concentration variability, and 65.4% and 67.2% of the TP concentration variability during the storage and discharge period, respectively. Based on the variable importance in the projection (VIP) values, soil erodibility had significant effects on the TN and TP concentrations. The key factors affecting the TN concentration were the slope gradient, basin relief, topographic wetness index, forest and agricultural land use, whereas the factors controlling the TP concentration were the landscape shape index, edge density, Shannon's diversity index and grass land use, although the TP concentration was also controlled by the patch density and contagion during the storage period, and by mean patch size and largest patch index during the discharge period. This study provides critical insights into sustainable landscape planning and effective reservoir water quality management.

Respiratory muscle ultrasonography: methodology, basic and advanced principles and clinical applications in ICU and ED patients-a narrative review

Respiratory muscle ultrasound is used to evaluate the anatomy and function of the respiratory muscle pump. It is a safe, repeatable, accurate, and non-invasive bedside technique that can be successfully applied in different settings, including general intensive care and the emergency department. Mastery of this technique allows the intensivist to rapidly diagnose and assess respiratory muscle dysfunction in critically ill patients and in patients with unexplained dyspnea. Furthermore, it can be used to assess patient-ventilator interaction and weaning failure in critically ill patients. This paper provides an overview of the basic and advanced principles underlying respiratory muscle ultrasound with an emphasis on the diaphragm. We review different ultrasound techniques useful for monitoring of the respiratory muscle pump and possible therapeutic consequences. Ideally, respiratory muscle ultrasound is used in conjunction with other components of critical care ultrasound to obtain a comprehensive evaluation of the critically ill patient. We propose the ABCDE-ultrasound approach, a systematic ultrasound evaluation of the heart, lungs and respiratory muscle pump, in patients with weaning failure.

An early neuroprotective effect of atorvastatin against subarachnoid hemorrhage

Atorvastatin has been shown to reduce early brain edema and neuronal death after subarachnoid hemorrhage, but its mechanism is not clear. In this study, rat models of subarachnoid hemorrhage were established by autologous blood injection in the cisterna magna. Rat models were intragastrically administered 20 mg/kg atorvastatin 24 hours before subarachnoid hemorrhage, 12 and 36 hours after subarachnoid hemorrhage. Compared with the controls, atorvastatin treatment demonstrated that at 72 hours after subarachnoid hemorrhage, neurological function had clearly improved; brain edema was remarkably relieved; cell apoptosis was markedly reduced in the cerebral cortex of rats; the number of autophagy-related protein Beclin-1-positive cells and the expression levels of Beclin-1 and LC3 were increased compared with subarachnoid hemorrhage only. The ultrastructural damage of neurons in the temporal lobe was also noticeably alleviated. The similarities between the effects of atorvastatin and rapamycin were seen in all the measured outcomes of subarachnoid hemorrhage. However, these were contrary to the results of 3-methyladenine injection, which inhibits the signaling pathway of autophagy. These findings indicate that atorvastatin plays an early neuroprotective role in subarachnoid hemorrhage by activating autophagy. The experimental protocol was approved by the Animal Ethics Committee of Anhui Medical University, China (904 Hospital of Joint Logistic Support Force of PLA; approval No. YXLL-2017-09) on February 22, 2017.

Mid-infrared spectroscopy tracing of channel erosion in highly erosive catchments on the Chinese Loess Plateau

Whether channel erosion or topsoil erosion constitutes the dominant erosion process throughout in the hilly region of the Chinese Loess Plateau (CLP), which suffers perhaps the most severe soil erosion in the world, had been controversial for a long time. The present article attempts to use the mid-infrared (MIR) spectroscopy fingerprinting method to trace sediment sources within nine small catchments in the hilly region of the CLP. Two major categories of sediment sources are identified: channel sediment and topsoil. Sediments trapped by check dams are used as the final sediment transferred by soil erosion. Discriminant analysis shows that MIR spectroscopy can differentiate between the two kinds of source sediments very well. The contributions of channel sediment and topsoil to the total final sediment are quantified using partial least squares regression (PLSR) analyses of MIR spectra to compare the trapped sediment samples with experimental models. The results of the root mean square error of calibration, root mean square error of validation and coefficient of determination for 18 models all show that the MIR-PLSR models boast very high prediction abilities in the nine catchments. A comparison between the geochemical fingerprinting method and the MIR spectroscopy method in one catchment reveals that although the two methods agree well on the channel sediment contributions, the two methods produce a significant difference (R² = 0.4). Overall, the MIR-PLSR results show that channel sediments contribute 19% to 66% of the total sediment with an average of 33 ± 16% in the nine small catchments. Our results indicate that although channel bank sediment is important, topsoil erosion is the predominant process in small dam-controlled catchments on the CLP. Furthermore, the MIR spectroscopy fingerprinting method can provide a useful, non-destructive, rapid and inexpensive tool for tracing sediment sources from different kinds of loess.

Efficacy and safety of endovascular thrombectomy in mild ischemic stroke: results from a retrospective study and meta-analysis of previous trials

Background

Mechanical thrombectomy has been proven as a standard care for moderate to severe ischemic stroke with anterior large vessel occlusion (LVO); however, whether it is equally effective in mild ischemic stroke (MIS) is controversial.

Methods

In this retrospective study, a total of 177 Chinese patients presenting with MIS (NIHSS ≤8) and LVO between January 2014 and September 2017 from seven comprehensive stroke centers were identified. Odds of good outcome with endovascular thrombectomy versus medical treatment were obtained by logistic regression analysis and propensity-score matching method, and a meta-analysis pooled results from six studies (n = 733).

Results

Good outcome (mRS: 0–1) was 58.2% (46/79) in the thrombectomy and 46.9% (46/98) in the medical group, which showed no statistical significance before adjustment (P = 0.13; OR = 1.57, 95% CI: 0.86 to 2.86). The adjusted ORs of thrombectomy versus medical group were 3.23 (95% CI, 1.35 to 7.73; P = 0.008) by multivariable logistic analysis, 2.78 (1.12 to 6.89; P = 0.02) by propensity score matching analysis, and 3.20 (1.22 to 8.37; P = 0.01) by propensity score matching analysis with additional adjustments, respectively. Thrombectomy treatment did not result in excessive mortality or symptomatic intracranial hemorrhage after adjustments. The meta-analysis did not confirm the associations between good outcome and endovascular treatment.

Conclusions

The current study indicates that endovascular thrombectomy is associated with good functional outcome in MIS patients with LVO, and without additional risk of symptomatic intracranial hemorrhage and mortality. Although the meta-analysis failed to demonstrate its superiority compared to medical treatment, randomized clinical trials are needed.

Electronic supplementary material

The online version of this article (10.1186/s12883-019-1372-9) contains supplementary material, which is available to authorized users.

[Gastrectomy with either wedge resection of the pancreas or pancreaticosplenectomy for adenocarcinoma of the esophagogastric junction invading the pancreas: a comparison study]

Objective: To compare the outcomes of gastrectomy with either wedge resection of the pancreas or pancreaticosplenectomy for adenocarcinoma of the esophagogastric junction (AEG) invading pancreas. Methods: From May 2005 to December 2015, a total of 64 patients with AEG invading pancreas underwent gastrectomy with either wedge resection of pancreas (n=25) or pancreaticosplenectomy (n=39) at Department of Thoracic Surgery, Fourth Hospital, Hebei Medical University. There were 53 males and 11 females, with a mean age of 60.2 years (range: 39 to 77 years). According to the AJCC esophageal cancer staging system, 8(th) edition, there were 27 patients in phase T4N0M0, 18 in phase T4bN1M0, 9 in phase T4bN2M0 and 10 in phase T4bN3M0. Follow-up was carried out every 6 months. The t-test for the measurement data and the χ(2) test, Fisher exact test or Wilcoxon ran-sum test for the enumeration data were used between the two groups. Survival curves were generated using the Kaplan-Meier method, and compared using the Log-rank test. Multivariate analysis was undertaken using the Cox proportional hazard model (forward stepwise regression). Results: In 39 patients who underwent pancreaticosplenectomy, incision infection occurred in 5 patients, anastomotic leak, peritoneal infection, lung infarction each occurred in 1 patient. There was 1 respiratory failure and 1 peritoneal infection in 25 patients undergoing wedge resection of the pancreas. There were no significant difference in the incidence of postoperative complications between the 2 groups (8/39 vs. 2/25, P=0.292), and no postoperative death in the study. Fifty-seven patients were followed up, with a follow-up rate of 89.1%. The 5-year overall survival rate was 32.3% in patients who underwent simultaneous gastrectomy and pancreaticosplenectomy, compared to 0 in those who underwent gastrectomy and wedge resection of the pancreas (χ(2)=4.484, P=0.034). The 5-year overall survival rate for patients who undergoing adjuvant chemotherapy was 32.3%, compared to 17.2% in whom underwent surgery alone (χ(2)=4.186, P=0.041). Conclusions: Survival benefit from R0 resection by simultaneous gastrectomy and pancreaticosplenectomy for AEG invading the pancreas can be achieved. Adjuvant chemotherapy is necessary for these patients.

Infections under Skin Flap After Cranioplasty and a Simple Effective Treatment

AIM

To report treatment experiences with titanium mesh cranioplasty infection at a single institution over the last 5 years.

MATERIAL AND METHODS

We retrospectively reviewed 11 consecutive patients who were diagnosed with infection under the skin flap after titanium mesh cranioplasty and received our new treatment between Feb 2008 and Feb 2013. We performed a 2- to 6-year follow-up to evaluate prognosis and security.

RESULTS

All 11 patients were cured and discharged, and all saved their infected bone flap (titanium mesh) completely. There was no recurrence of infection after follow-up for 2-6 years.

CONCLUSION

Sensitive antibiotics combined with enclosed continuous irrigation and drainage is a safe, easy, economical and effective treatment for infection after titanium mesh cranioplasty that can save the infected bone flap.

Hydrological response of a large-scale mountainous watershed to rainstorm spatial patterns and reforestation in subtropical China

This paper aims to investigate the hydrological response of a large-scale (8973 km²) mountainous watershed to different rainstorm spatial patterns and reforestation. Based on 32 years of observations, measurements of 184 rainstorm events and 125 sediment-producing events with complete hydrographs were analyzed. The K-means clustering method was used to classify the spatial patterns of rainstorm events in accordance with their event-based spatial rainfall characteristics. The 184 rainstorm events were classified into four spatial patterns, among which the spatial features differ significantly: (I) Spatial Pattern I (SPI) includes rainstorms with a low amount of cumulative areal rainfall (27.4 mm), the highest spatial variability (0.986), and the highest frequency; (II) Spatial Pattern II (SPII) includes rainstorms of high spatial variability (0.759) and the largest amount of local maximum daily rainfall (106.8 mm); (III) Spatial Pattern III (SPIII) includes rainstorms with a medium amount of cumulative areal rainfall (58.7 mm) and low spatial variability (0.362); and (IV) Spatial Pattern IV (SPIV) includes rainstorms with the largest amount of cumulative areal rainfall (117.2 mm) and the lowest spatial variability (0.313). Vegetation cover in the upper Du watershed was significantly improved after the implementation of the Grain-for-Green project. The average area-specific sediment yields (SSY) for the four SPs were 15.4, 65.5, 55.8, and 286.2 t km^-2 before reforestation and decreased to 6.0, 59.3, 43.7 and 89.9 t km^-2, respectively, after reforestation. ANOVA (analysis of variance) indicated that reforestation resulted in a significant reduction in runoff coefficient under SPIII and SPIV and a significant reduction in SSY under SPI and SPIV. A hysteresis analysis suggested that the proportion of events with a clockwise loop increased from 64.9% before reforestation to 82.1% after reforestation and that complex loops became less common during 2000-2010 under SPIV, thereby implying a reduced sediment supply.

Assessing breathing effort in mechanical ventilation: physiology and clinical implications

Recent studies have shown both beneficial and detrimental effects of patient breathing effort in mechanical ventilation. Quantification of breathing effort may allow the clinician to titrate ventilator support to physiological levels of respiratory muscle activity. In this review we will describe the physiological background and methodological issues of the most frequently used methods to quantify breathing effort, including esophageal pressure measurement, the work of breathing, the pressure-time-product, electromyography and ultrasound. We will also discuss the level of breathing effort that may be considered optimal during mechanical ventilation at different stages of critical illness.

Positive End-Expiratory Pressure Ventilation Induces Longitudinal Atrophy in Diaphragm Fibers

RATIONALE

Diaphragm weakness in critically ill patients prolongs ventilator dependency and duration of hospital stay and increases mortality and healthcare costs. The mechanisms underlying diaphragm weakness include cross-sectional fiber atrophy and contractile protein dysfunction, but whether additional mechanisms are at play is unknown.

OBJECTIVES

To test the hypothesis that mechanical ventilation with positive end-expiratory pressure (PEEP) induces longitudinal atrophy by displacing the diaphragm in the caudal direction and reducing the length of fibers.

METHODS

We studied structure and function of diaphragm fibers of mechanically ventilated critically ill patients and mechanically ventilated rats with normal and increased titin compliance.

MEASUREMENTS AND MAIN RESULTS

PEEP causes a caudal movement of the diaphragm, both in critically ill patients and in rats, and this caudal movement reduces fiber length. Diaphragm fibers of 18-hour mechanically ventilated rats (PEEP of 2.5 cm H2O) adapt to the reduced length by absorbing serially linked sarcomeres, the smallest contractile units in muscle (i.e., longitudinal atrophy). Increasing the compliance of titin molecules reduces longitudinal atrophy.

CONCLUSIONS

Mechanical ventilation with PEEP results in longitudinal atrophy of diaphragm fibers, a response that is modulated by the elasticity of the giant sarcomeric protein titin. We postulate that longitudinal atrophy, in concert with the aforementioned cross-sectional atrophy, hampers spontaneous breathing trials in critically ill patients: during these efforts, end-expiratory lung volume is reduced, and the shortened diaphragm fibers are stretched to excessive sarcomere lengths. At these lengths, muscle fibers generate less force, and diaphragm weakness ensues.

Use of esophageal balloon pressure-volume curve analysis to determine esophageal wall elastance and calibrate raw esophageal pressure: a bench experiment and clinical study

BACKGROUND

Accurate measurement of esophageal pressure (Pes) depends on proper filling of the balloon. Esophageal wall elastance (Ees) may also influence the measurement. We examined the estimation of balloon-surrounding elastance in a bench model and investigated a simplified calibrating procedure of Pes in a balloon with relatively small volume.

METHODS

The Cooper balloon catheter (geometric volume of 2.8 ml) was used in the present study. The balloon was progressively inflated in different gas-tight glass chambers with different inner volumes. Chamber elastance was measured by the fitting of chamber pressure and balloon volume. Balloon pressure-volume (P-V) curves were obtained, and the slope of the intermediate linear section was defined as the estimated chamber elastance. Balloon volume tests were also performed in 40 patients under controlled ventilation. The slope of the intermediate linear section on the end-expiratory esophageal P-V curve was calculated as the Ees. The balloon volume with the largest Pes tidal swing was defined as the best volume. Pressure generated by the esophageal wall during balloon inflation (Pew) was estimated as the product of Ees and best volume. Because the clinical intermediate linear section enclosed filling volume of 0.6 to 1.4 ml in each of the patient, we simplified the estimation of Ees by only using parameters at these two filling volumes.

RESULTS

In the bench experiment, bias (lower and upper limits of agreement) was 0.5 (0.2 to 0.8) cmH₂O/ml between the estimated and measured chamber elastance. The intermediate linear section on the clinical and bench P-V curves resembled each other. Median (interquartile range) Ees was 3.3 (2.5-4.1) cmH₂O/ml. Clinical best volume was 1.0 (0.8-1.2) ml and ranged from 0.6 to 1.4 ml. Estimated Pew at the best volume was 2.8 (2.5-3.5) cmH₂O with a maximum value of 5.2 cmH₂O. Compared with the conventional method, bias (lower and upper limits of agreement) of Ees estimated by the simple method was - 0.1 (- 0.7 to 0.6) cmH₂O/ml.

CONCLUSIONS

The slope of the intermediate linear section on the balloon P-V curve correlated with the balloon-surrounding elastance. The estimation of Ees and calibration of Pes were feasible for a small-volume-balloon.

TRIAL REGISTRATION

Identifier NCT02976844 . Retrospectively registered on 29 November 2016.

Use of Cardiac Cycle Locating to Minimize the Influence of Cardiac Artifacts on Esophageal Pressure Measurement During Dynamic Occlusion Test

BACKGROUND

The dynamic occlusion test is used to guide balloon catheter placement during esophageal pressure (P_es) monitoring. We introduced a cardiac cycle locating method to attenuate the influence of cardiac artifacts on P_es measurement. The aim was to provide a reliable analytic algorithm for the occlusion test.

METHODS

Esophageal balloon catheters were placed in subjects receiving pressure support ventilation. During balloon position adjustment, end-expiratory occlusion was performed to induce 3 consecutive inspiratory efforts. P_es and airway pressure (P_aw) data were collected for off-line analysis. For each occluded inspiratory effort, the change in P_es (ΔP_es) was plotted against the change in P_aw (ΔP_aw), and the slope of the regression line was calculated. The ΔP_es/ΔP_aw ratio was also measured with the cardiac cycle locating method and peak-to-peak method. Bland-Altman analysis was used to assess the agreement between the ΔP_es/ΔP_aw ratio and the slope. We defined the occlusion test with all fitted slopes for the 3 inspiratory efforts within 0.8 to 1.2 to indicate optimal balloon position; otherwise, the position was deemed non-optimal. Using the slope as the reference, the diagnostic accuracy of the ΔP_es/ΔP_aw ratio in distinguishing the optimal and the non-optimal balloon position was analyzed.

RESULTS

A total of 86 occlusion tests containing 258 inspiratory efforts were collected from 15 subjects. The median (interquartile range) slope of ΔP_es versus ΔP_aw plot was 0.85 (0.76, 0.91). Bias (lower and upper limit of agreement) of ΔP_es/ΔP_aw ratio measured by the cardiac cycle locating method and the peak-to-peak method was 0.02 (-0.13 to 0.16) and 0.06 (-0.18 to 0.31), respectively. Forty-five (52.3%) occlusion tests indicated optimal balloon positions. Compared to the peak-to-peak method, the cardiac cycle locating method was more specific in detecting the non-optimal position.

CONCLUSIONS

The cardiac cycle locating method provided reliable and precise measurement for the occlusion test. This method can accurately detect non-optimal balloon position during catheter adjustment.

Bispectral Index Can Reliably Detect Deep Sedation in Mechanically Ventilated Patients: A Prospective Multicenter Validation Study

BACKGROUND

Excessively deep sedation is prevalent in mechanically ventilated patients and often considered suboptimal. We hypothesized that the bispectral index (BIS), a quantified electroencephalogram instrument, would accurately detect deep levels of sedation.

METHODS

We prospectively enrolled 90 critically ill mechanically ventilated patients who were receiving sedation. The BIS was monitored for 24 hours and compared with the Richmond Agitation Sedation Scale (RASS) evaluated every 4 hours. Deep sedation was defined as a RASS of -3 to -5. Threshold values of baseline BIS (the lowest value before RASS assessment) and stimulated BIS (the highest value after standardized assessment) for detecting deep sedation were determined in a training set (45 patients, 262 RASS assessments). Diagnostic accuracy was then analyzed in a validation set (45 patients, 264 RASS assessments).

RESULTS

Deep sedation was only prescribed in 6 (6.7%) patients, but 76 patients (84.4%) had at least 1 episode of deep sedation. Thresholds for detecting deep sedation of 50 for baseline and 80 for stimulated BIS were identified, with respective areas under the receiver-operating characteristic curve of 0.771 (95% confidence interval, 0.714-0.828) and 0.805 (0.752-0.857). The sensitivity and specificity of baseline BIS were 94.0% and 66.5% and of stimulated BIS were 91.0% and 66.5%. When baseline and stimulated BIS were combined, the sensitivity, specificity, and clinical utility index were 85.0% (76.1%-91.1%), 85.9% (79.5%-90.7%), and 66.9% (57.8%-76.0%), respectively.

CONCLUSIONS

Combining baseline and stimulated BIS may help detect deep sedation in mechanically ventilated patients.

Optimal esophageal balloon volume for accurate estimation of pleural pressure at end-expiration and end-inspiration: an in vitro bench experiment

BACKGROUND

Esophageal pressure, used as a surrogate for pleural pressure, is commonly measured by air-filled balloon, and the accuracy of measurement depends on the proper balloon volume. It has been found that larger filling volume is required at higher surrounding pressure. In the present study, we determined the balloon pressure-volume relationship in a bench model simulating the pleural cavity during controlled ventilation. The aim was to confirm whether an optimal balloon volume range existed that could provide accurate measurement at both end-expiration and end-inspiration.

METHODS

We investigated three esophageal balloons with different dimensions and materials: Cooper, SmartCath-G, and Microtek catheters. The balloon was introduced into a glass chamber simulating the pleural cavity and volume-controlled ventilation was initiated. The ventilator was set to obtain respective chamber pressures of 5 and 20 cmH₂O during end-expiratory and end-inspiratory occlusion. Balloon was progressively inflated, and balloon pressure and chamber pressure were measured. Balloon transmural pressure was defined as the difference between balloon and chamber pressure. The balloon pressure-volume curve was fitted by sigmoid regression, and the minimal and maximal balloon volume accurately reflecting the surrounding pressure was estimated using the lower and upper inflection point of the fitted sigmoid curve. Balloon volumes at end-expiratory and end-inspiratory occlusion were explored, and the balloon volume range that provided accurate measurement at both phases was defined as the optimal filling volume.

RESULTS

Sigmoid regression of the balloon pressure-volume curve was justified by the dimensionless variable fitting and residual distribution analysis. All balloon transmural pressures were within ±1.0 cmH₂O at the minimal and maximal balloon volumes. The minimal and maximal balloon volumes during end-inspiratory occlusion were significantly larger than those during end-expiratory occlusion, except for the minimal volume in Cooper catheter. Mean (±standard deviation) of optimal filling volume both suitable for end-expiratory and end-inspiratory measurement ranged 0.7 ± 0.0 to 1.7 ± 0.2 ml in Cooper, 1.9 ± 0.2 to 3.6 ± 0.3 ml in SmartCath-G, and 2.2 ± 0.2 to 4.6 ± 0.1 ml in Microtek catheter.

CONCLUSIONS

In each of the tested balloon, an optimal filling volume range was found that provided accurate measurement during both end-expiratory and end-inspiratory occlusion.

Effect of High-Flow Nasal Cannula Oxygen Therapy Versus Conventional Oxygen Therapy and Noninvasive Ventilation on Reintubation Rate in Adult Patients After Extubation: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

PURPOSE

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the effect of high-flow nasal cannula (HFNC) on reintubation in adult patients.

PROCEDURES

Ovid Medline, Embase, and Cochrane Database of Systematic Reviews were searched up to November 1, 2016, for RCTs comparing HFNC versus conventional oxygen therapy (COT) or noninvasive ventilation (NIV) in adult patients after extubation. The primary outcome was reintubation rate, and the secondary outcomes included complications, tolerance and comfort, time to reintubation, length of stay, and mortality. Dichotomous outcomes were presented as risk ratio (RR) with 95% confidence intervals (CIs) and continuous outcomes as weighted mean difference and 95% CIs. The random effects model was used for data pooling.

FINDINGS

Seven RCTs involving 2781 patients were included in the analysis. The HFNC had a similar reintubation rate compared to either COT (RR, 0.58; 95% CI, 0.21-1.60; P = .29; 5 RCTs, n = 1347) or NIV (RR, 1.11; 95% CI, 0.88-1.40; P = .37; 2 RCTs, n = 1434). In subgroup of critically ill patients, the HFNC group had a significantly lower reintubation rate compared to the COT group (RR, 0.35; 95% CI, 0.19-0.64; P = .0007; 2 RCTs, n = 632; interaction P = .07 compared to postoperative subgroup). Qualitative analysis suggested that HFNC might be associated with less complications and improved patient's tolerance and comfort. The HFNC might not delay reintubation. Trial sequential analysis on the primary outcome showed that required information size was not reached.

CONCLUSION

The evidence suggests that COT may still be the first-line therapy in postoperative patients without acute respiratory failure. However, in critically ill patients, HFNC may be a potential alternative respiratory support to COT and NIV, with the latter often associating with patient intolerance and requiring a monitored setting. Because required information size was not reached, further high-quality studies are required to confirm these results.

Lung-protective Ventilation in Patients with Brain Injury: A Multicenter Cross-sectional Study and Questionnaire Survey in China

Background:

Over the years, the mechanical ventilation (MV) strategy has changed worldwide. The aim of the present study was to describe the ventilation practices, particularly lung-protective ventilation (LPV), among brain-injured patients in China.

Methods:

This study was a multicenter, 1-day, cross-sectional study in 47 Intensive Care Units (ICUs) across China. Mechanically ventilated patients (18 years and older) with brain injury in a participating ICU during the time of the study, including traumatic brain injury, stroke, postoperation with intracranial tumor, hypoxic-ischemic encephalopathy, intracranial infection, and idiopathic epilepsy, were enrolled. Demographic data, primary diagnoses, indications for MV, MV modes and settings, and prognoses on the 60^th day were collected. Multivariable logistic analysis was used to assess factors that might affect the use of LPV.

Results:

A total of 104 patients were enrolled in the present study, 87 (83.7%) of whom were identified with severe brain injury based on a Glasgow Coma Scale ≤8 points. Synchronized intermittent mandatory ventilation (SIMV) was the most frequent ventilator mode, accounting for 46.2% of the entire cohort. The median tidal volume was set to 8.0 ml/kg (interquartile range [IQR], 7.0–8.9 ml/kg) of the predicted body weight; 50 (48.1%) patients received LPV. The median positive end-expiratory pressure (PEEP) was set to 5 cmH₂O (IQR, 5–6 cmH₂O). No PEEP values were higher than 10 cmH₂O. Compared with partially mandatory ventilation, supportive and spontaneous ventilation practices were associated with LPV. There were no significant differences in mortality and MV duration between patients subjected to LPV and those were not.

Conclusions:

Among brain-injured patients in China, SIMV was the most frequent ventilation mode. Nearly one-half of the brain-injured patients received LPV. Patients under supportive and spontaneous ventilation were more likely to receive LPV.

Trial Registration:

ClinicalTrials.org NCT02517073 https://clinicaltrials.gov/ct2/show/NCT02517073.

Use of the injection test to indicate the oesophageal balloon position in patients without spontaneous breathing: a clinical feasibility study

Objective

To investigate the clinical feasibility of the injection test for balloon placement during oesophageal pressure measurement in patients without spontaneous breathing.

Methods

The injection test was performed in 12 mechanically ventilated patients under deep sedation and paralysis. During withdrawal of the balloon from the stomach and air injection into the gastric lumen of the catheter, the presence of the injection test wave in the balloon pressure tracing indicated that the whole balloon was positioned above the lower oesophageal sphincter (LES). The positive pressure occlusion test was performed at different balloon positions.

Results

In each patient, the injection test wave appeared at a distinct balloon depth, with a mean ± standard deviation of 41.9 ± 3.3 cm and range from 37 cm to 47 cm. The optimal ratio of changes in the balloon and airway pressure (0.8–1.2) during the positive pressure occlusion test was obtained when the balloon was located 5 cm and 10 cm above the LES in nine (75%) and three (25%) patients, respectively.

Conclusions

The injection test is feasible for identification of the whole balloon position above the LES during passive ventilation. The middle third of the oesophagus might be the optimal balloon position.

Post-craniotomy intracranial infection in patients with brain tumors: a retrospective analysis of 5723 consecutive patients

AIM

To determine the risk factors for and the incidence, outcomes, and causative pathogens of post-craniotomy intracranial infection (PCII) in patients with brain tumors.

METHODS

A retrospective study was performed of 5723 patients with brain tumors who were surgically treated between January 2012 and December 2013 in Beijing Tiantan Hospital. The patients' demographics, pathohistological diagnoses, surgical procedures, postoperative variables, causative pathogens, and outcomes were evaluated.

RESULTS

The overall incidence of PCII was 6.8%, and 82.1% of all cases were diagnosed within two weeks after the craniotomy. Postoperative administration of antibiotics reduced the incidence of PCII. Independent risk factors included clean-contaminated craniotomy, prolonged operation (> 7 h), external cerebrospinal fluid (CSF) drainage/monitoring device placement, and postoperative CSF leakage. Patients ≤ 45 years old were more susceptible to infection. Compared with supratentorial tumors, tumors located in the infratentorial or intraventricular regions were more vulnerable to PCII. Gram-positive bacteria were the most common causative pathogens isolated from the CSF samples, accounting for 82.0% of the PCII cases.

CONCLUSIONS

Risk factors for PCII can be identified early in the perioperative period. These findings raise the possibility of improving the clinical outcomes of patients with brain tumors who undergo craniotomy.

Endoscopy-assisted cerebral falx incision via unilateral approach for treatment of dissymmetric bilateral frontal contusion

OBJECTIVE

To investigate the clinical features and treatment strategy of dissymmetric bilateral frontal contusion, and to summarize our experience in treating these patients by minimally invasive surgery.

METHODS

Over the past 3 years, we have treated a total of 31 patients with dissymmetric bilateral frontal contusion using endoscopy-assisted unilateral cerebral falx incision. Other 30 patients treated by routine bilateral approaches within the same period were taken as control.

RESULTS

Seventeen cases (54.8%) in the unilateral operation group survived and were in good condition, 8 (25.8%) had moderate disability, 4 (12.9%) had severe disability, 1 (3.2%) was in vegetative state, and 1 (3.2%) died. Compared with the control group, the Glasgow Outcome Scale score was not significantly different in the unilateral operation group, but the operation time, blood transfusion volume, the length of hospital stay, the incidences of mental disorder and olfactory nerve injury were greatly reduced in the unilateral operation group.

CONCLUSIONS

Endoscopy-assisted unilateral cerebral falx incision can shorten the operation time, reduce surgical trauma and complications in treatment of patients with dissymmetric bilateral frontal contusion. It can obviously diminish the chance of delayed intracerebral hematoma and subsequently minimize the incidences of subfalcial and centrencephalic herniation.

MicroRNA-128a-induced apoptosis in HTR-8/SVneo trophoblast cells contributes to pre-eclampsia

INTRODUCTION

Pre-eclampsia (PE) can endanger the survival of the mother and fetus. Currently, the pathogenesis of PE is not completely understood and no fundamental therapeutics are available. The present study was performed to determine the function of miR-128a in HTR-8/SVneo trophoblast cells and to ascertain its underlying role in the pathogenesis of PE.

METHODS

We investigated the function of miR-128a in HTR-8/SVneo cells by overexpressing. We analyzed the apoptosis of HTR-8/SVneo cells by performing apoptosis assays and measured the loss of mitochondrial membrane potential (Δym), the generation of reactive oxygen species (ROS) and caspase activity. In addition, miR-128a target genes were predicted.

RESULTS

Using computer-based programs, we identified Bax as a direct target of miR-128a. In the apoptosis assays of HTR-8/SVneo cells, miR-128a decreased the Δψm, depleted ATP levels and increased ROS generation, cytochrome c release as well as caspase activation. Further studies showed that miR-128a induced the apoptosis of HTR-8/SVneo cells by down-regulating Bax through the mitochondrial apoptosis pathway.

CONCLUSIONS

miR-128a is an up-regulated miRNA in patient with PE. Our study demonstrated that the miR-128a-induced apoptosis of HTR-8/SVneo cells may contribute to PE and miR-128a may be a novel potential therapeutic target for PE.

Designed synthesis of Zr-based ceria–zirconia–neodymia composite with high thermal stability and its enhanced catalytic performance for Rh-only three-way catalyst

The Zr-based CeO₂–ZrO₂–Nd₂O₃ composite oxide materials with excellent thermal stability were synthesized by co-precipitation combined with a simple mechanical mixing process.

Ce-Zr-La/Al2O3 prepared in a continuous stirred-tank reactor: a highly thermostable support for an efficient Rh-based three-way catalyst

Two Ce-Zr-La/Al2O3 composite oxides, CZLA-C and CZLA-B, were synthesized using a co-precipitation method in a continuous stirred-tank reactor (CSTR) and a batch reactor (BR), respectively. Two Rh-based three-way catalysts (TWCs), Rh/CZLA-C and Rh/CZLA-B were obtained by a wet-impregnation method using the two composites as the supports. The physicochemical properties of the samples before and after thermal treatment at 1000 °C were characterized by N2 adsorption-desorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), H2-temperature programmed reduction (H2-TPR) and CO chemisorption. The results indicated that CZLA-C shows higher thermal stability than CZLA-B due to a sparsely-agglomerated morphology. Compared with Rh/CZLA-B, Rh/CZLA-C displayed better reducibility and higher thermal stability and exhibited significantly higher activity in the catalytic removal of the simulated gasoline vehicle exhaust emission (NO, CO and C3H8). Our work can provide a facile and economical synthesis route to advanced support materials and catalysts for exhaust emission control.

Molecular characterization, expression, and functional analysis of NOD1 in Qingyuan partridge chicken

Nucleotide-binding oligomerization domain-containing protein-1 (NOD1) is a cytoplasmic pattern recognition receptor (PRR) and a key member of the NOD-like receptor (NLR) family. It has been reported that NLRs recognize a variety of microbial infections to induce the host innate immune response via modulation of NF-κB signaling. However, no reports on chicken NOD1 have been reported to date. In the current study, the full-length cDNA sequence of NOD1 was cloned. The complete open reading frame of NOD1 contains 2856 bp and encodes a 951 amino acid protein. Structurally, it is comprised of one caspase recruitment domain at the N-terminus, seven leucine-rich repeat regions at the C-terminus, and one NACHT domain between the N and C-termini. Phylogenetic analyses showed that chicken NOD1 clusters with duck and turkey. Furthermore, tissue-specific expression analyses of chicken NOD1 were performed using quantitative reverse transcription-PCR. NOD1 is widely distributed in various tissues, with the highest expression observed in testes. Finally, induced expression of chNOD1 and its associated adaptor molecule receptor-interacting protein 2, as well as the effector molecule NF-κB, was observed following S. enterica serovar Enteritidis infection. These findings highlight the important role of chicken NOD1 in response to pathogenic invasion. The present study is the first report of the cloning, expression, and functional analysis of chicken NOD1 and provides the foundation for future research on the structure and function of chicken NOD1.

Risk of postoperative deep venous thrombosis in patients with colorectal cancer treated with open or laparoscopic colorectal surgery: a meta-analysis

INTRODUCTION

Whether the incidence rate of deep venous thrombosis (DVT) between laparoscopic and open colorectal cancer surgery the same or not were under the debated without conclusion. The aim of this study was to compare the incidence of DVT after laparoscopic or open colorectal cancer surgery by meta-analysis.

MATERIALS AND METHODS

The open published articles comparing the incidence of DVT after laparoscopic or open colorectal cancer were collected in the data bases of Medline, the Cochrane central register of controlled trials and CNKI. The relative risk (RR) was pooled by using random or fixed effect mode to evaluate the incidence of DVT between laparoscopic or open colorectal cancer surgery.

RESULTS

After searching the databases, 9 randomized clinical studies with 2606 colorectal cancer cases were included in this meta-analysis. The mean operation time was 201.8 ± 17.28 min with its range of 180.0-224.4 min in the laparoscopic surgery group and 148.1 ± 18.8 min with its range of 135.0-184.0 min in the open surgery group. The operation time for laparoscopic surgery group were significant lower than in the open surgery group (P < 0.05). The RR of DVT between the laparoscopy and open surgery groups was 0.71 with its 95% confidence interval of 0.35-1.45 (P = 0.35).

CONCLUSIONS

The operation time in laparoscopic colorectal cancer surgery was statistical longer than in the open colorectal cancer surgery, but the DVT risk of the two surgery approach was not different according to this meta-analysis.

Mother-derived trans-generational immune priming in the red palm weevil, Rhynchophorus ferrugineus Olivier (Coleoptera, Dryophthoridae)

Rhynchophorus ferrugineus (Coleoptera, Curculionidae) is the most destructive pest of palm trees worldwide containing it invasive areas, such as the southern part of China. It is always emphasized to develop integrated pest management based on biological agents, but their success is not very exciting. Presently, the immune defenses of this pest against biological agents attract scarce attention. It is still unclear whether immune priming also generally occurs in insect pests and in response to different pathogens. Our results indicated that previous challenge of bacteria pathogen enhanced the magnitude of phenoloxidase activity and antibacterial activity in R. ferrugineus larvae against the secondary infection. Furthermore, trans-generational immune priming was also determined in this pest, and only challenged R. ferrugineus mothers transferred the immune protection to their offspring which suggested males and females of this pest might have evolved different strategies on the investment of delivering immune protection to their offspring. Importantly, our data provide the evidence to suggest that different kinds of biological control agents might be used alternatively or in combination to fight against R. ferrugineus because of the existence of immune priming with low species-specific level. On the other hand, for this invasive pest, the immune priming may also facilitate its adaptation and dispersal in the new regions.

Assessing regional environmental quality by integrated use of remote sensing, GIS, and spatial multi-criteria evaluation for prioritization of environmental restoration

This study was an attempt to analyse the regional environmental quality with the application of remote sensing, geographical information system, and spatial multiple criteria decision analysis and, to project a quantitative method applicable to identify the status of the regional environment of the study area. Using spatial multi-criteria evaluation (SMCE) approach with expert knowledge in this study, an integrated regional environmental quality index (REQI) was computed and classified into five levels of regional environment quality viz. worse, poor, moderate, good, and very good. During the process, a set of spatial criteria were selected (here, 15 criterions) together with the degree of importance of criteria in sustainability of the regional environment. Integrated remote sensing and GIS technique and models were applied to generate the necessary factors (criterions) maps for the SMCE approach. The ranking, along with expected value method, was used to standardize the factors and on the other hand, an analytical hierarchy process (AHP) was applied for calculating factor weights. The entire process was executed in the integrated land and water information system (ILWIS) software tool that supports SMCE. The analysis showed that the overall regional environmental quality of the area was at moderate level and was partly determined by elevation. Areas under worse and poor quality of environment indicated that the regional environmental status showed decline in these parts of the county. The study also revealed that the human activities, vegetation condition, soil erosion, topography, climate, and soil conditions have serious influence on the regional environment condition of the area. Considering the regional characteristics of environmental quality, priority, and practical needs for environmental restoration, the study area was further regionalized into four priority areas which may serve as base areas of decision making for the recovery, rebuilding, and protection of the environment.

Use of dexmedetomidine for prophylactic analgesia and sedation in delayed extubation patients after craniotomy: a study protocol and statistical analysis plan for a randomized controlled trial

BACKGROUND

Pain and agitation are common in patients after craniotomy. They can result in tachycardia, hypertension, immunosuppression, increased catecholamine production and increased oxygen consumption. Dexmedetomidine, an alpha-2 agonist, provides adequate sedation without respiratory depression, while facilitating frequent neurological evaluation.

METHODS/DESIGN

The study is a prospective, randomized, double-blind, controlled, parallel-group design. Consecutive patients are randomly assigned to one of the two treatment study groups, labeled 'Dex group' or 'Saline group.' Dexmedetomidine group patients receive a continuous infusion of 0.6 μg/kg/h (10 ug/ml). Placebo group patients receive a maintenance infusion of 0.9% sodium chloride for injection at a volume and rate equal to that of dexmedetomidine. The mean percentages of time in optimal sedation, vital signs, various and adverse events, the percentage of patients requiring propofol for rescue to achieve/maintain targeted sedation (Sedation-Agitation Scale, SAS 3 to 4) and total dose of propofol required throughout the study drug infusion are collected. The percentage of patients requiring fentanyl for additional rescue to analgesia and total dose of fentanyl required are recorded. The effects of dexmedetomidine on hemodynamic and recovery responses during extubation are measured. Intensive care unit and hospital length of stay also are collected. Plasma levels of epinephrine, norepinephrine, dopamine, cortisol, neuron-specific enolase and S100-B are measured before infusion (T1), at two hours (T2), four hours (T3) and eight hours (T4) after infusion and at the end of infusion (T5) in 20 patients in each group.

DISCUSSION

The study has been initiated as planned in July 2012. One interim analysis advised continuation of the trial. The study will be completed in July 2013.

TRIAL REGISTRATION

ClinicalTrials (NCT): ChiCTR-PRC-12002903.

Factors influencing delayed extubation after infratentorial craniotomy for tumour resection: a prospective cohort study of 800 patients in a Chinese neurosurgical centre

OBJECTIVES

To investigate prospectively the rate of, and factors influencing, delayed extubation following infratentorial craniotomy in a Chinese neurosurgical centre.

METHODS

Patients undergoing infratentorial craniotomy for tumour resection were prospectively enrolled and stratified according to whether extubation was attempted in the operating theatre (early extubation) or not (delayed extubation). Pre- and intraoperative variables were collected and analysed. Multiple logistic regression analysis was performed, to identify factors related to delayed extubation.

RESULTS

The study included 800 patients, 398 (49.8%) of whom underwent delayed extubation. The overall rate of extubation failure was 3.6%. Independent factors related to delayed extubation were: preoperative lower cranial nerve dysfunction; hydrocephalus; tumour location; duration of surgery ≥ 6 h; estimated blood loss ≥ 1000 ml. Compared with patients in the early extubation group, those in the delayed extubation group had a higher rate of pneumonia, longer intensive care unit and postoperative hospital stays, and higher hospitalization costs.

CONCLUSIONS

Brain stem and lower cranial nerve function were the main factors affecting extubation decision-making. Further research is required, to establish criteria for delayed extubation following infratentorial craniotomy.

CLIC1 protein: a candidate prognostic biomarker for malignant-transformed hydatidiform moles

OBJECTIVES

The purpose of this study was to identify prognostic biomarkers indicating malignant transformation of hydatidiform moles (HMs).

METHODS

Two-dimensional gel electrophoresis-based proteomic approach was used to compare the protein profiles of complete benign moles (3 samples) with those of malignant-transformed moles (3 samples). Matrix-assisted laser desorption/ionization time of flight mass spectrometry was used to identify differentially expressed proteins. Western blot was used to verify the results of 2-dimensional gel electrophoresis, and immunohistology was used to explore the function of these proteins in gestational trophoblastic disease.

RESULTS

Eighteen proteins, deregulated in the malignant-transformed group compared with the benign group (ratio ≥ 2; P < 0.05), were identified. A bioinformatic analysis indicated that most of these 18 proteins were involved in the processes of cell proliferation and cell survival. Among the 18 proteins, chloride intracellular channel protein 1 (CLIC1) was chosen for further study. Our results showed that the levels of CLIC1 expression in choriocarcinoma tissue were higher than in complete HM tissue (P < 0.01). Chloride intracellular channel protein 1 expression was increased in the tissues of malignant-transformed HMs compared with nontransformed HMs (P < 0.01).

CONCLUSION

Our findings suggest that CLIC1 could be a potential new prognostic biomarker for hydatidiform mole that undergoes malignant transformation.

[Expression of RhoGDI alpha in human testes and sperm and its correlation with the success rate of IVF]

OBJECTIVE

To investigate the expression of RhoGDIalpha in human testes and spermatozoa, and compare the expression of RhoGDIalpha in the ejaculated spermatozoa from normozoospermic me and infertile patients men receiving in vitro fertilization (IVF).

METHODS

The localization of RhoGDIalpha in the human testis was determined by immunohistochemistry, and that in the pre-capacitated, capacitated and acrosome-reacted sperm by immunofluorescence. Western blot was used to detect the expression of RhoGDIalpha in the semen samples obtained from normozoospermic males (n = 10), IVF patients with high fertilization rates (> or = 60%, n = 12) and those with low fertilization rates (< 60%, n = 13).

RESULTS

Immunohistochemistry showed that the RhoGDIalpha protein was located in all spermatogenic cells and highly expressed in the elongated spermatids. Immunofluorescence exhibited a high expression of RhoGDIalpha in the acrosome and flagellum of human sperm, which decreased in the acrosome after capacitation and disappeared after acrosome reaction. Western blot revealed an obviously decreased expression of RhoGDIalpha in the spermatozoa of the IVF patients with low fertilization rates (0.66 +/- 0.18), with statistically significant difference from those with high fertilization rates (0.97 +/- 0.17) and the normozoospermic men (1.13 +/- 0.21).

CONCLUSION

The RhoGDIalpha protein is located in the acrosome and flagellum of human sperm, and might be involved in sperm movement, capacitation and acrosome reaction. The significantly reduced expression of RhoGDIalpha in the sperm of low-fertilization patients suggests that it may be a new diagnostic biomarker for male infertility, and has a potential application value in sperm selection for IVF.

Design of shared instruments to utilize simulated gravities generated by a large-gradient, high-field superconducting magnet

A high-field superconducting magnet can provide both high-magnetic fields and large-field gradients, which can be used as a special environment for research or practical applications in materials processing, life science studies, physical and chemical reactions, etc. To make full use of a superconducting magnet, shared instruments (the operating platform, sample holders, temperature controller, and observation system) must be prepared as prerequisites. This paper introduces the design of a set of sample holders and a temperature controller in detail with an emphasis on validating the performance of the force and temperature sensors in the high-magnetic field.

Role of translation by mitochondrial-type ribosomes during sperm capacitation: an analysis based on a proteomic approach

Mammalian spermatozoa contain a complex population of mRNAs, some of which have been demonstrated to be translated de novo by mitochondrial-type ribosomes using D-chloramphenicol (CP), a specific inhibitor of mitochondrial translation. However, little is known about the functions of these mRNAs in mature sperm. In the present study, differential proteomic approaches were applied to study sperm protein profiles translated by mitochondrial-type ribosomes using the inhibitor CP and 44 proteins were identified with lower expression in CP-treated sperm in comparison to capacitated sperm (ratio >or= 1.5, p<0.05). Results of Western blot and real-time PCR suggest that four proteins were translated by mitochondrial-type ribosomes. Bioinformatics analysis indicated that 26 of 44 proteins were involved in some critical processes correlated to sperm-egg interaction event. In addition, Mups, whose functions in reproduction have never been studied, were chosen for further study. Our results showed that Mups proteins were localized to the acrosome and flagellum of precapacitated sperm, and were also expressed in the equatorial segment of capacitated sperm. The depletion of Mups using neutralizing antibodies significantly inhibited capacitation in a dose-dependent manner, subsequently inhibited acrosome reaction and sperm-egg fusion. In summary, mitochondrial translation during capacitation can store proteins beneficial for sperm-egg interaction.

First Report of Botrytis Gray Mold on Red Bayberry in China

Red bayberry (Myrica rubra Sieb. et Zucc) is a special fruit produced in southeastern China. Heavy losses due to postharvest rot and short shelf-life have negatively affected farmers' incomes. In June 2007, a survey was conducted to determine the causal agents of red bayberry (cv. Dongkui) rot in Linhai City, Zhejiang Province. Only a few soft rot fruits with typical gray mold of Botrytis cinerea were found on trees, but 74% (266 of 360) of the fruits that appeared disease free during harvest showed a mass of gray mold after 5 days in storage at 22°C. Brown conidiophores bore botryose heads of hyaline, ellipsoid, unicellular conidia, measuring 9.1 to 16.1 × 8.6 to 11.0 μm. Mycelia were initially whitish and turned gray with age. Black, irregular sclerotia were formed in potato dextrose agar medium. Such features suggested B. cinerea infection (1). Pathogenicity was confirmed by inoculation of 20 healthy red bayberries with a conidial suspension (10⁶/ml); 100% were infected and masses of gray mold were formed 4 days after inoculation. No mock-inoculated fruits were infected. To confirm involvement of B. cinerea, the internal transcribed spacer (ITS) region was amplified with primers ITS4/ITS6 (2). The sequence (Accession No. AM884742) matched 100% to B. cinerea sequences deposited in Genbank (Accession Nos. EF207415, EF207414, and EF207413). To our knowledge, this is the first report of red bayberry rot caused by B. cinerea in China. References: (1) J. Y. Lu. Phytopathogenic Fungi. Chinese Agricultural Publishing, Beijing, 1995. (2) D. E. L. Cooke and J. M. Duncan. Mycol. Res. 101:667, 1997.

[Toll-like receptor 4 signal pathway may be involved in cerebral ischemic tolerance induced by hypoxic preconditioning: experiment with rats]

OBJECTIVE

To investigate the role of Toll-like receptor 4 (TLR4) inflammatory signal pathway in brain ischemic tolerance induced by hypoxia preconditioning (HP).

METHODS

160 Wistar rats were randomly divided into 4 groups: asphyxial cardiac arrest (ACA) group (n = 54, subjected to ACA for 4 min and then resuscitation), HP + ACA group [n = 44, subjected to apnea and ventilation (HP) for 1 min 4 times with an interval of 5 min between each 2 times, and then subjected to apnea for 4 min and resuscitation 24 h later), HP group (n = 42, subjected to HP 4 times only), and sham operation group (Group C, n = 20). The mortality within 24 h after resuscitation and circulatory functions were observed. Neurodeficit score (NDS) was recorded 24, 48, and 72 hours after successful resuscitation. Rats were killed 1, 3, 6, 12, 24, 48, and 72 h after preconditioning or operation to take out the left brain cortex. RT-PCR was used to detect the mRNA expression of TLR4. The levels of nuclear factor-kappaB (NFkappaB), tumor necrosis factor-alpha (TNF-alpha), and interleukin (IL)-6 were detected by relevant kits.

RESULTS

The mortality of the HP + ACA group was 5%, significantly lower than that of ACA group (30%, P < 0.01). The NDS levels at different time points of the HP group and Group C were all 100 +/- 0. The NDS levels of the HP + ACA group and ACA group at different time points were all significantly lower than those of the control group and HP group (all P < 0.01). The NDS levels at different time points of the ACA group were all significantly lower than those of the HP + ACA group (all P < 0.05). The NDS levels 72 h later of the HP + ACA and ACA groups were both significantly higher than those 24 h later of the corresponding groups (both P < 0.05). The TLR4 mRNA expression of the control group at any time points were all very weak, and the TLR4 mRNA expression level of the other groups increased since 1 h after hypoxia gradually and decreased 72 h later. The NFkappaB expression levels of the control group at any time points were all very weak, and the NFkappaB expression level of the other groups increased time-dependently since 1 h later, peaked 3 - 6 h later, and began to decrease 24 h later. There was a tendency of increase of NFkappaB expression level in the order of HP group < HP + ACA group < ACA group. The expression of TNF-alpha and IL-6 showed the same tendency as seen in the expression of TLR2 and NFkappaB.

CONCLUSION

HP induces brain ischemic tolerance via a possible mechanism of activating TLR4 signal pathway and then inhibiting inflammatory response induced by ACA.

Lack of intraspecific biological variation between two geographical populations of Oomyzus sokolowskii (Hymenoptera: Eulophidae), a gregarious larval-pupal parasitioid of Plutella xylostella (Lepidoptera: Plutellidae)

The chalcid, Oomyzus sokolowskii Kurdjumov has been recorded in many parts of the world as a major larval-pupal, gregarious endoparasitoid of the diamondback moth, Plutella xylostella (Linnaeus), a serious pest of brassica vegetable crops worldwide. This study investigated intraspecific variation between two populations of O. sokiolowskii, one from Cape Verde Islands, West Africa and the other from Hangzhou, China. In all crosses and backcrosses between the two geographical populations, the numbers of progeny and sex ratio of progeny were similar to those obtained within each of the populations, demonstrating complete reproductive compatibility between the two populations. The two populations showed similar responses to temperature with respect to development time and survival of immature stages. Observations on the interactions between the two O. sokolowskii populations and Cotesia plutellae (Kurdjumov), another major parasitoid of P. xylostella, showed that neither population could achieve successful parasitism of P. xylostella larvae already parasitized by C. plutellae. However, both O. sokolowskii populations could achieve hyperparasitism by ovipositing into a mid-late stage larva of C. plutellae developing inside the primary host. Contrary to earlier reports, no evidence of intraspecific variations in ability to hyperparasitize between these two populations of O. sokolowskii was found.