18 research outputs found
Improved strategy for post-traumatic hydrocephalus following decompressive craniectomy: Experience of a single center
BackgroundPatients with head trauma may develop hydrocephalus after decompressive craniectomy. Many studies have referred one-stage cranioplasty (CP) and ventriculoperitoneal shunt (VPS) was applied to treat cranial defect with post-traumatic hydrocephalus (PTH), but the safety and efficiency of the procedure remain controversial.MethodsThis is a retrospective cohort study including 70 patients of PTH following decompressive craniectomy who underwent simultaneous (50) and separated (20) procedures of cranioplasty and VPS from March 2014 to March 2021 at the authors’ institution with at least 30 days of follow-up. Patient characteristics, clinical findings, and complications were collected and analyzed.ResultsFifty patients with PTH underwent improved simultaneous procedures and 20 patients underwent staged surgeries. Among the cases, the overall complication rate was 22.86%. Complications suffered by patients who underwent one-stage procedure of CP and VPS did not differ significantly, compared with patients in the group of staged procedures (22% vs. 25%, p = 0.763). The significant difference was not observed in the two groups, regarding the complications of subdural/epidural fluid collection (4%/6% vs. 0/2%, p = 1.000/1.000), epidural hemorrhage (6% vs. 4%, p = 0.942), dysfunction of shunting system (0 vs. 2%, p = 0.286), postoperative seizure (8% vs. 4%, p = 1.000), and reoperation case (0 vs. 2%, p = 0.286). No case of subdural hemorrhage, incision/intracranial/abdominal infection, shunting system dysfunction, or reoperation was observed in the group of simultaneous procedure. Complications including subdural/epidural fluid collection, subdural hemorrhage, and incision/intracranial infection were not shown in the case series of the staged procedure group.ConclusionThe improved simultaneous procedure of cranioplasty and VPS is effective and safe to treat cranial defect and post-traumatic hydrocephalus with low risk of complications
Dual Synthetic Jet Actuator and Its Applications—Part IV: Analysis of Heat Dissipation and Entropy Generation of Liquid Cooling with Dual Synthetic Jet Actuator
Increasing heat flux restricts the development of the miniaturization of electronic devices. There is an urgent need for a heat dissipation method that will efficiently cool the chip. This paper presents a novel liquid cooling device based on dual synthetic jets actuator (DSJA) technology. The characteristics of the temperature and velocity field of the device are numerically studied by a three-dimensional coupled heat transfer model. The entropy generation rate caused by heat transfer and fluid friction was studied to analyze the effective work loss and irreversibility of the heat transfer process. When the DSJA is turned on, the temperature of the heat source with a heat flux of 200 W/cm2 is 73.07 ∘C, and the maximum velocity is 24.32 m/s. Compared with the condition when the the DSJA is closed, the temperature decreases by 25.15 ∘C, and the velocity increases by nearly 20 m/s. At this time, the total inlet flow is 1.26 L/min. The larger frictional entropy generation is mainly distributed near the inlet and outlet of the channel and the jet orifice. The higher the velocity is, the more obvious the frictional entropy generation is. Due to the large temperature gradient, there is a large thermal entropy generation rate at the fluid–solid interface
Dual Synthetic Jet Actuator and Its Applications—Part IV: Analysis of Heat Dissipation and Entropy Generation of Liquid Cooling with Dual Synthetic Jet Actuator
Increasing heat flux restricts the development of the miniaturization of electronic devices. There is an urgent need for a heat dissipation method that will efficiently cool the chip. This paper presents a novel liquid cooling device based on dual synthetic jets actuator (DSJA) technology. The characteristics of the temperature and velocity field of the device are numerically studied by a three-dimensional coupled heat transfer model. The entropy generation rate caused by heat transfer and fluid friction was studied to analyze the effective work loss and irreversibility of the heat transfer process. When the DSJA is turned on, the temperature of the heat source with a heat flux of 200 W/cm2 is 73.07 ∘C, and the maximum velocity is 24.32 m/s. Compared with the condition when the the DSJA is closed, the temperature decreases by 25.15 ∘C, and the velocity increases by nearly 20 m/s. At this time, the total inlet flow is 1.26 L/min. The larger frictional entropy generation is mainly distributed near the inlet and outlet of the channel and the jet orifice. The higher the velocity is, the more obvious the frictional entropy generation is. Due to the large temperature gradient, there is a large thermal entropy generation rate at the fluid–solid interface
Characterization of variation induced by low-energy N + and cloning of differentially expressed cDNA of a mutant in Arabidopsis thaliana *
Medulla oblongata hemorrhage after acupuncture: A case report and review of literature
Secondary hemorrhage occurs as a complication of central nervous system (CNS) following acupuncture has been reported in few cases. The present study reports a case of a 70-year-old woman who presents medulla oblongata hemorrhage after acupuncture. The patient suffered severe headache, neck pain, vomiting, and weakness after the neck acupuncture. The purpose of presenting this case report is to raise awareness among clinicians of fateful CNS complications during acupuncture. More importantly, qualified training of acupuncturists is anticipated and standardized processes of clinical acupuncture operations needs to be developed, in order to avoid the occurrence of acupuncture accidents. Keywords: Secondary hemorrhage, Medulla oblongata, Acupuncture, Complicatio
The Beneficial Effects of Quercetin, Curcumin, and Resveratrol in Obesity
Over the past two decades, obesity has been one of the major public health concerns in most countries. In the search for new molecules that could be used for the treatment of obesity, good perspectives have been opened up for polyphenols, a class of natural bioactive phytochemicals. Experimental and limited clinical trial evidence supports that some polyphenols such as quercetin, curcumin, and resveratrol have potential benefit functions on obesity treatment. This brief review focuses on the main functions of the above-named polyphenols on adipose tissue. These polyphenols may play beneficial effects on adipose tissue under obese condition by alleviating intracellular oxidative stress, reducing chronic low-grade inflammation, inhibiting adipogenesis and lipogenesis, and suppressing the differentiation of preadipocytes to mature adipocytes
The Influence of Steady Air Jet on the Trailing-Edge Shock Loss in a Supersonic Compressor Cascade
To effectively reduce shock wave loss at the trailing edge of a supersonic cascade under high back-pressure, a shock wave control method based on air jets is proposed. The air jet was arranged on the pressure side of the blade in the upstream of the trailing-edge shock. The flow control mechanism and effects of parameters were analyzed by computational methods. The results show that the air jet formed an oblique shock wave in the cascade passage which decelerated and pressurized the airflow. The resulting expansion wave downstream of the jet slot weakened the strength of the trailing-edge shock. This could effectively change the normal shock into oblique shock and thus weaken the shock loss. Optimal control effect was achieved when the mass flow rate ratio of the jet to the passage airflow remained 0.35–1.11% and the distance from the jet slot to the shock foot of the trailing-edge shock was about five times the thickness of the boundary layer. The proposed method can reduce the total pressure loss of a supersonic cascade, with the maximum improvement effect reaching 7.29% compared to the no-control state
Anomalous polarization enhancement in a van der Waals ferroelectric material under pressure
Abstract CuInP2S6 with robust room-temperature ferroelectricity has recently attracted much attention due to the spatial instability of its Cu cations and the van der Waals (vdW) layered structure. Herein, we report a significant enhancement of its remanent polarization by more than 50% from 4.06 to 6.36 µC cm−2 under a small pressure between 0.26 to 1.40 GPa. Comprehensive analysis suggests that even though the hydrostatic pressure suppresses the crystal distortion, it initially forces Cu cations to largely occupy the interlayer sites, causing the spontaneous polarization to increase. Under intermediate pressure, the condensation of Cu cations to the ground state and the polarization increase due cell volume reduction compensate each other, resulting in a constant polarization. Under high pressure, the migration of Cu cations to the center of the S octahedron dominates the polarization decrease. These findings improve our understanding of this fascinating vdW ferroelectric material, and suggest new ways to improve its properties
A comparative study of daytime-based methane emission from two wetlands of Nepal Himalaya
Natural wetlands constitute one of the major sources of methane emission to the atmosphere. Data on methane emission from wetlands on southern slopes of the Himalaya (SSH) have not been reported so far. Such data are very valuable for filling the gap and generating the whole emission patterns at regional or even global scale. We selected two wetlands at different altitudinal locations in Nepal, i.e. Beeshazar Lake (286 m a.s.l.) and Dhaap Lake (2089 m a.s.l.), to monitor the daytime methane emissions in monsoon season and dry season separately. Daytime methane emission varied between monsoon and dry seasons and also across different plant communities. The daytime methane emission variations were stronger in dry season than in monsoon season. The source/sink strengths of the two selected plant communities in each wetland were significantly different, presenting the strong spatial variation of methane emission within wetland. The methane emissions recorded in monsoon season were significantly higher (7.74 +/- 6.49 mg CH4 m(-2) h(-1) and 1.00 +/- 1.23 mg CH4 m(-2) h(-1) in low and high altitude wetlands, respectively) than those in dry season (1.84 +/- 4.57 mg CH4 m(-2) h(-1) and 0.27 +/- 0.71 mg CH4 m(-2) h(-1) in low and high altitude wetlands, respectively). Methane emissions from the low altitude wetland were significantly higher than those from the high altitude wetland in both of the seasons. Plant community height, standing water depth and soil temperature correlated to the methane emission from wetlands in this region. (C) 2015 Elsevier Ltd. All rights reserved
Comparative transcriptome combined with morpho-physiological analyses revealed key factors for differential cadmium accumulation in two contrasting sweet sorghum genotypes
Cadmium (Cd) is a widespread soil contaminant threatening human health. As an ideal energy plant, sweet sorghum (Sorghum bicolor (L.) Moench) has great potential in phytoremediation of Cd-polluted soils, although the molecular mechanisms are largely unknown. In this study, key factors responsible for differential Cd accumulation between two contrasting sweet sorghum genotypes (high-Cd accumulation one H18, and low-Cd accumulation one L69) were investigated. H18 exhibited a much higher ability of Cd uptake and translocation than L69. Furthermore, Cd uptake through symplasmic pathway and Cd concentrations in xylem sap were both higher in H18 than those in L69. Root anatomy observation found the endodermal apoplasmic barriers were much stronger in L69, which may restrict the Cd loading into xylem. The molecular mechanisms underlying these morpho-physiological traits were further dissected by comparative transcriptome analysis. Many genes involved in cell wall modification and heavy metal transport were found to be Cd-responsive DEGs and/or DEGs between these two genotypes. KEGG pathway analysis found phenylpropanoid biosynthesis pathway was over-represented, indicating this pathway may play important roles in differential Cd accumulation between two genotypes. Based on these results, a schematic representation of main processes involved in differential Cd uptake and translocation in H18 and L69 is proposed, which suggests that higher Cd accumulation in H18 depends on a multilevel coordination of efficient Cd uptake and transport, including efficient root uptake and xylem loading, less root cell wall binding, and weaker endodermal apoplasmic barriers