In this paper, the aerodynamic noise of a centrifugal fan with an eccentric impeller is investigated and analyzed by adopting a hybrid method combining detached-eddy simulation and the acoustic ...finite element method (FEM). The impeller-eccentric effect of high-speed centrifugal fans, frequently ignored in theoretical studies, is objective in practical engineering applications owing to machining and installation errors, which have a significant influence on flow characteristics and subsequently noise characteristics. An impeller-whirling model combined with the sliding mesh method is introduced to obtain the actual flow with an eccentric impeller. First, the internal flow field handled with different eccentricities is investigated. The total pressure and internal efficiency decline, and the flow field near the leading edge shows intense unsteadiness, inducing a rise in the pressure fluctuation amplitude at the rotating frequency (RF) in both impeller flow passage and volute domain. Second, the variational formulation of Lighthill's analogy is implemented by acoustic FEM to better account for the interaction between the solid surface and aerodynamic sound, capturing a contribution by turbulence noise at the second RF. Under eccentric conditions, the sound source intensity shows a circumferential non-uniform distribution in a similar region to the flow field. The calculated sound pressure level captures the variation in the experimental result, which shows an obvious rise at RF induced by the impeller-eccentric effect. The characteristics of the noise spectrum and sound directivity change significantly, and the overall sound pressure level rises with the increase in eccentricity. This study provides an effective simulation strategy for predicting the aerodynamic noise of centrifugal fans under realistic conditions.
•IGF-1 decreases in the spinal cord after chemotherapy.•IGF-1 is mainly expressed in astrocytes while IGF-1R exclusively on neurons in the spinal cord.•Chemotherapy up-regulates neuroinflammation ...(IL-17A & TNF-α) and nociceptive neuropeptides.•Treatment with rIGF-1 rescues CIPN and attenuates the spinal inflammatory response.
Chemotherapy-induced peripheral neuropathy (CIPN) is a common and intractable complication in chemotherapy-receiving patients. Insulin-like growth factor-1 (IGF-1) is a popular neurotrophin with various functions, such as maintaining neuronal survival and synaptic functioning in the central nervous system. Therefore, we hypothesized that the IGF-1 signaling pathway could be a candidate target for treating CIPN.
We established the CIPN model by injecting mice intraperitoneally with oxaliplatin and assessed IGF-1 protein expression, its receptor IGF1R, phospho-IGF1R (p-IGF1R), interleukin-17A (IL-17A), tumor necrosis factor-α (TNF-α), and calcitonin gene-related peptide (CGRP) in the lumbar spinal cord with Western blot and immunofluorescence. To examine the effect of IGF-1 signaling on CIPN, we injected mice intrathecally or intraperitoneally with mouse recombinant IGF-1 (rIGF-1).
IGF-1 protein expression decreased significantly in the spinal cord on D3 and D10 (the 3rd and 10th days after beginning oxaliplatin chemotherapy) and was co-localized with astrocytes primarily in the lumbar spinal cord, whereas IGF1R was predominantly expressed on neurons. Both intrathecally- and intraperitoneally-administered rIGF-1 relieved the chemotherapy-induced pain-like behavior and reduced IL-17A, TNF-α, and CGRP protein expressions in the spinal cord.
Our results indicate a vital role for IGF-1 signaling in CIPN. Targeting IGF-1 signaling could be a potent therapeutic strategy for treating CIPN in clinical settings.
Objective
To analyze the factors causing failure of primary surgery in congenital scoliosis (CS) patients with single hemivertebra (SHV) undergoing posterior spinal fusion, and to elucidate the ...revision strategies.
Methods
In this retrospective study, a total of 32 CS patients secondary to SHV undergoing revision surgery from April 2010 to December 2017 due to failed primary surgery with more than 2 years follow‐up were reviewed. The reasons for failure of primary surgery and revision strategies were analyzed for each patient. The radiographic parameters including coronal Cobb angle, segmental kyphosis (SK), coronal balance (CB), and sagittal vertical axis (SVA) were compared between pre‐ and post‐revision. The complications during revision and follow‐up were recorded.
Results
The mean age at revision surgery of the 32 CS patients was 15.8 ± 9.7 years and the average duration between primary and revision surgery was 31.0 ± 35.4 months. The reasons for failed primary surgery were severe post‐operative curve progression of focal scoliosis in 14 cases (43.8%), implant failure in 17 (53.1%) and trunk imbalance in 12 (37.5%). The candidate revision strategies included thorough resection of residual hemivertebra and adjacent discs, extending fusion levels, complete pseudarthrosis resection, massive bone graft, replacement of broken rods, satellite rod fixation, horizontalization of upper/lower instrumented vertebrae and rigid fusion of structural compensatory curves were performed individually. After revision surgery, the coronal Cobb angle, SK, CB and SVA showed significant improvement (P < 0.05) with no significant correction loss during follow‐up (P > 0.05). The intra‐operative complications included alarming changes of neurologic monitoring in three (9.4%) patients and dual tear in two, while rod fracture re‐occurred was detected in one patient at 18 months after revision.
Conclusions
The common reasons for failed primary surgery in CS patients with SHV undergoing posterior spinal fusion were severe post‐operative curve progression of focal scoliosis, implant failure and trunk imbalance. The revision strategies including thorough resection of residual hemivertebra and adjacent discs, extended fusion levels to structural curvature, complete pseudarthrosis resection, massive bone graft, replacement of broken internal fixation and horizontalization of upper/lower instrumented vertebrae should be individualized based on the causes of failed primary surgery.
The common reasons for failed primary surgery in CS patients with SHV undergoing posterior spinal fusion were severe post‐operative curve progression of focal scoliosis, implant failure and trunk imbalance. The revision strategies including resection of residual hemivertebra, extended fusion levels, complete pseudarthrosis resection, replacement of fixation and horizontalization of UIV/LIV.
•Ventilated supercavitation with drag-reduction (DR) additives was simulated.•DR additives could further reduce the drag resistance on underwater bodies.•DR additives could affect the formation of ...ventilated supercavitation.
The hydrodynamic characteristics of axisymmetric ventilated supercavitating flows influenced by drag-reduction additives are numerically studied. The Cross viscosity model, a shear-thinning model, is employed to characterize the rheological feature of the aqueous solution of the drag-reduction additives. First, the numerical calculation procedure is established and verified, and the numerical results are in good agreement with the existing correlations. And then the air–liquid two-phase and air–liquid-vapor three-phase ventilated supercavitating flows in water and drag-reducing solution, respectively, are investigated. The flow resistance and morphological characteristics of the ventilated supercavities are mainly analyzed. It is obtained that the drag-reduction additives mainly influence the friction drag when the supercavities have not fully formed. The friction drag reduction rate can reach up to 49.66% and 58.13% in the two-phase and three-phase flows, respectively, in the currently investigated cases. Moreover, the vapor region caused by natural cavitation is larger in the drag-reducing solution.
Vitamin D deficiency is common in critically ill patients, and was reported to be associated with adverse outcomes. However, the effect of vitamin D deficiency on mortality in critically ill patients ...remains unclear.
We searched PubMed and EMBASE from the inception to July 2014 for cohort studies to assess the effect of vitamin D deficiency on the incidence of mortality in critically ill patients. Mortality-specific odds ratio (OR) with 95% confidence interval (CI) were pooled with a random- or fixed-effect models when appropriate.
Seven cohort studies with a total of 4,204 participants including 1,679 cases of vitamin D deficiency were included in this meta-analysis. Vitamin D deficiency was significantly associated with an increased hospital mortality (OR 1.76; 95% CI, 1.38 to 2.24; P < 0.001), with very low heterogeneity (I (2) = 2.3%; P = 0.402). The finding of increased hospital mortality in critically ill adult patients was consistently found in every stratum of our subgroup analyses.
This meta-analysis suggests that vitamin D deficiency is associated with increased incidence of hospital mortality in critically ill adult patients.
Objective
To evaluate the effect of creatine phosphate sodium on bispectral index (BIS) and recovery quality during the general anaesthesia emergence period in elderly patients.
Methods
This ...randomized, double-blind, placebo-controlled study enrolled patients undergoing transabdominal cholecystectomy under general anaesthesia. Patients were randomly assigned to receive either creatine phosphate sodium (1.0 g/100 ml 0.9% saline; group P) or 100 ml 0.9% saline (group C) over 30 minutes during surgical incision. The BIS values were recorded at anaesthesia induction (T0), skin incision (T1), cutting the gallbladder (T2), suturing the peritoneum (T3), skin closure (T4), sputum suction (T5), extubation (T6) and 1 min (T7), 5 min (T8), 10 min (T9), and 15 min (T10) after extubation. The anaesthesia duration, operation time, waking time, extubation time, consciousness recovery time, time in the postanaesthesia care unit (PACU), and the Steward recovery scores at T7, T8, T9 and T10 were recorded.
Results
A total of 120 elderly patients were randomized equally to the two groups. Compared with group C, the BIS values were significantly higher in group P at T5, T6, T7 and T8; and the Steward recovery scores at T7 and T8 were significantly higher in group P. The waking time, extubation time, consciousness recovery time and time in the PACU were significantly shorter in group P compared with group C.
Conclusion
Creatine phosphate sodium administered during transabdominal cholecystectomy can improve BIS values and recovery following general anaesthesia in elderly patients.
•Infralimbic BDNF decreases after inflammatory pain.•Infralimbic BDNF infusion alleviates CFA induced thermal hyperalgesia and mechanical allodynia.•Consecutive infralimbic BDNF infusion accelerates ...recovery process of inflammatory pain.
In chronic pain, it has been reported that the medial prefrontal cortex (mPFC) takes important regulatory roles, and may change functionally and morphologically in result of chronic pain. Brain-derived neurotrophic factor (BDNF) is well known as a critical modulator of neuronal excitability and synaptic transmission in the central nervous system. The aim of the present study is to investigate the role of BDNF in the infralimbic cortex and the prelimbic cortex of the mPFC in complete Freund’s adjuvant (CFA)-induced inflammatory pain. We found that the BDNF level decreased in the infralimbic cortex, but not in the prelimbic cortex, 3days after the CFA induction of the inflammatory pain. BDNF infusion into bilateral infralimbic cortices to activate neuronal activities could alleviate inflammatory pain and accelerate long-term recovery from pain. In conclusion, BDNF in the infralimbic cortex of the mPFC could accelerate recovery from inflammatory pain.
Abstract It is widely known that exogenous formaldehyde exposure induces human cognitive impairment and animal memory loss; and recent studies show that formaldehyde at pathological levels induces Aβ ...deposition and misfolding of tau protein to form globular amyloid-like aggregates. Endogenous formaldehyde may be a marker for progressive senile dementia. The aim of this study was to investigate the correlation of endogenous formaldehyde in urine of senile dementia and mini mental state examination (MMSE) scores. Formaldehyde level was analyzed by high-performance liquid chromatography (with fluorescence detection) in human urine from dementia patients ( n = 141), patients with hypertension ( n = 33) or diabetes ( n = 16) and healthy individuals ( n = 38), autopsy hippocampus samples from Alzheimer's disease (AD) patients and brains of three types of AD animal model: namely, senescence accelerated mice (SAMP8), APP-transgenic mice and APP/PS1-transgenic mice. In a double-blind study, there was marked elevation of urine formaldehyde levels in patients ( n = 91) with dementia, and a slight increase in patients ( n = 50) with mild cognitive impairment. Urine formaldehyde level was inversely correlated with mini mental state examination scores ( R s = −0.441, p < 0.0001). Furthermore, formaldehyde levels were significantly increased in the autopsy hippocampus from Alzheimer's patients ( n = 4). In SAMP8 brains the formaldehyde level was significantly increased, suggesting that the endogenous formaldehyde is related to aging in mice. The brain formaldehyde level in APP/PS1-transgenic ( n = 8) mice at age of 3 months and APP-transgenic ( n = 8) mice at age of 6 months was increased (0.56 ± 0.02 mM), respectively, as compared with their respective age-matched controls, when these two types of AD-like animals, respectively, started to form Aβ deposits and memory loss obviously. According to the level of formaldehyde in the brain of the transgenic mice, we treated normal mice with formaldehyde (0.5 mM, intraperitoneal administration) and observed the memory loss of the animal in Morris water maze trial. Cognitive impairments for the senile dementia are probably related to endogenous formaldehyde levels; and the mini mental state examination scores referred to the evaluation of urine formaldehyde level in dementia patients may be used as a non-invasive method for the investigation and diagnosis of senile dementia.
Activation of the cholecystokinin type B receptor (CCKBR) by cholecystokinin octapeptide (CCK-8) inhibits opioid analgesia. Chronic opiate treatment leads to an increase in the CCK-8 concentration ...and thus enhances the antagonism of CCK-8 against opioid analgesia; the underlying molecular mechanisms remain of great interest. In the present study, we validated the colocalization of the μ-opioid receptor (MOR) and CCKBR in pain signal transmission-related spinal cord dorsal horn and dorsal root ganglion neurons of rats. Co-immunoprecipitation (Co-IP) and fluorescence lifetime-imaging-microscopy-based fluorescence resonance energy transfer (FLIM-FRET) assays showed that MOR heteromerized with CCKBR directly in transfected HEK293 cells. Combined with MOR mutant construction, the third transmembrane domain of MOR (TM3
) was demonstrated to participate in heteromerization with CCKBR. Receptor ligand binding, ERK phosphorylation and cAMP assays showed that MOR heteromerization with CCKBR weakened the activity of MOR. A cell-penetrating interfering peptide consisting of TM3
and TAT (a transactivator of HIV-1) sequences from the N terminal to the C terminal disrupted the MOR-CCKBR interaction and restored the activity of MOR in transfected HEK293 cells. Furthermore, intrathecal application of the TM3
-TAT peptide alleviated CCK-8-injection-induced antagonism to morphine analgesia in rats. These results suggest a new molecular mechanism for CCK-8 antagonism to opioid analgesia in terms of G-protein-coupled receptor (GPCR) interaction through direct heteromerization. Our study may provide a potential strategy for pain management with opioid analgesics.
Two new carboxyethyltin‐functionalized polyoxometalates (POMs) were successfully obtained and confirmed with physicochemical and spectroscopic methods including X‐ray crystallography. The lowest ...unoccupied molecular orbitals of both compounds are higher in energy than that of TiO2, and the optical band gaps of these compounds are smaller than that of TiO2. Grafting them onto a TiO2 film created two kinds of novel photoanode materials that showed significantly enhanced photovoltaic and photocurrent responses, as well as improved photoelectrooxidation activities for methanol relative to that shown by a single TiO2 film. Further, P2W15‐Co‐SnR produced the largest photocurrent by exploring the photoelectric activities of a series of carboxyethyltin POM derivatives. This work provides new insight into the photoelectrochemical functionalization of POM‐based organic–inorganic hybrids.
Get grafting: Two new carboxyethyltin‐functionalized armtype polyoxometalates (POMs) are designed to be grafted on TiO2 film; this has resulted in two novel kinds of photoanote materials with enhanced photocurrent and photoelectrocatalytic activity for methanol.
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