A microchip gas chromatography column assembly with a 3D metal printing micro column oven and a flexible stainless-steel column.

In this work, a microchip gas chromatography (GC) column assembly utilizing a three-dimensional (3D) printed micro oven and a flexible stainless steel capillary column was developed. The assembly's performance and separation capabilities were characterized. The key components include a 3D printed aluminum plate (7.50 × 7.50 × 0.16 cm) with a 3-meter-long circular spiral channel, serving as the oven, and the column coiled on the channel with an inner diameter of 320 µm and a stationary phase of OV-1. A heating ceramic plate was affixed on the opposite side of the plate. The assembly weighed 40.3 g. The design allows for easy disassembly, or stacking of heating devices and columns, enabling flexibility in adjusting column length. When using n-C13 as the test analyte at 140 °C, a retention factor (k) was 8.5, and 7797 plates (2599 plates/m) were obtained. The assembly, employing resistance heating, demonstrated effective separation performance for samples containing alkanes, aromatics, alcohols and ketones, with good reproducibility. The reduction in theoretical plates compared to oven heating was only 2.95 %. In the boiling point range of C6 to C18, rapid temperature programming (120 °C/min) was achieved with a power consumption of 119.512 W. The assembly was successfully employed to separate benzene series compounds, gasoline and volatile organic compounds (VOCs), demonstrating excellent separation performance. This innovative design addresses the challenges of the complexity and low repeatability of the fabrication process and the high cost associated with microchip columns. Furthermore, its versatility makes it suitable for outdoor analysis applications.

A systematic review and meta-analysis on abnormal posturing among brain injury patients.

BACKGROUND: Abnormal motor posturing (AMP), exhibiting as decorticate, decerebrate, or opisthotonos, is regularly noticed among children and adults. OBJECTIVE: This systematic review and meta-analysis examined the risk factors and outcome of posturing among severe head and brain injury subjects. METHODS: Based on the inclusion and exclusion criteria and using MeSH terms: "decerebrate posturing", "opisthotonic posturing", "brain injury", and/or "cerebral injury" articles were searched on Scopus, PubMed, Science Direct, and google scholar databases. Observational studies, case series, and case reports were included. RESULTS: A total of 1953 studies were retrieved initially, and based on the selection criteria, 20 studies were finally selected for review and were analyzed for meta-analysis based on the mortality between the hematomas. The functional outcomes of this study are the risk factors, mortality rate and Glasgow Outcome Scale. Decerebrative patients were higher among the studies related to head injury surgeries. Males were mainly treated for decerebrate postures compared with the female subjects. Extradural hematoma and acute subdural hematoma with cerebral contusion were quite common in the surgical mass lesions. CONCLUSION: The findings reported that the lesion types, the operative procedures, and the age of the decerebrating patients with brain injuries are the significant prognostic factors determining the survival outcomes.

ANTECEDENTES: Postura motora anormal (AMP), exibindo-se como decorticada, descerebrada ou opistótono, é regularmente observada entre crianças e adultos. OBJETIVO: Esta revisão sistemática e metanálise examinou os fatores de risco e os resultados da postura entre indivíduos com lesões graves na cabeça e no cérebro. MéTODOS: Com base nos critérios de inclusão e exclusão e usando termos MeSH: artigos sobre "postura descerebrada", "postura opistótona", "lesão cerebral" e/ou "lesão cerebral" foram pesquisados nas bases de dados Scopus, PubMed, Science Direct e Google Scholar. Foram incluídos estudos observacionais, séries de casos e relatos de casos. RESULTADOS: Um total de 1.953 estudos foram recuperados inicialmente e, com base nos critérios de seleção, 20 estudos foram finalmente selecionados para revisão e analisados para metanálise com base na mortalidade entre os hematomas. Os resultados funcionais deste estudo são os fatores de risco, taxa de mortalidade e Escala de Resultados de Glasgow. Os pacientes descerebrados foram maiores entre os estudos relacionados a cirurgias de traumatismo cranioencefálico. Os homens foram tratados principalmente para posturas descerebradas em comparação com as mulheres. Hematoma extradural e hematoma subdural agudo com contusão cerebral foram bastante comuns nas lesões de massa cirúrgica. CONCLUSãO: Os achados relataram que os tipos de lesões, os procedimentos operatórios e a idade dos pacientes descerebrados com lesões cerebrais são os fatores prognósticos significativos que determinam os resultados de sobrevivência.

Micromechanism for Copper-Deficiency Enhanced Stability: A Quasi In Situ TEM Study of Electric-Induced Structural Evolution in Cu2-x(S, Se) Liquid-Like Thermoelectric Materials.

Cu-based liquid-like thermoelectric materials have garnered tremendous attention due to their inherent ultralow lattice thermal conductivity. However, their practical application is hampered by stability issues under a large current or temperature gradient. It has been reported that introduction of copper vacancies can enhance the chemical stability, whereas the micromechanism behind this macroscopic improvement still remains unknown. Here, we have established a quasi in situ TEM method to examine and compare the structural evolution of Cu2-xS0.2Se0.8 (x = 0, 0.05) under external electric fields. It is then found that the preset Cu vacancies could favor the electric-induced formation of a more stable intermediate phase, i.e., the hexagonal CuSe-type structure in the form of either lamellar defects (majorly) or long-range order (minorly), in which ordering of S and Se also occurred. Thereby, copper and chalcogen atoms could largely be solidified into the matrix, and the elemental deposition and evaporation process is mitigated under an electric field.

Neuroprotective effects of Chrysanthemum morifolium on cerebral ischemia- reperfusion injury contributes to the oxidative stress suppression and related Keap1/Nrf2 pathway.

BACKGROUND: Ischemic stroke, the cause of death and disability worldwide, is closely related to oxidative stress damage. Chrysanthemum has profound antiantioxidant activity. We aimed to verify whether Chrysanthemum morifolium extract (CME) influences brain injury in cerebral ischemia-reperfusion injury (CR/RI) model. METHODS: In vitro, rat hippocampal H19-7 neurons were pretreated with CME, CR/RI was simulated with oxygen glucose deprivation/reoxygenation (OGD/R). The cell viability, apoptosis, lactate dehydrogenase release, reactive oxygen species (ROS) generation, malonaldehyde (MDA) content and superoxide dismutase（SOD） activity were detected. In vivo, middle cerebral artery occlusion (MCAO) model rats were pre-administered with CME, and then behavioral test, triphenyltetrazolium chloride (TTC), hematoxylin-eosin staining (HE), terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL), ROS immunofluorescence, MDA and SOD activity were tested. Furthermore, Keap1/Nrf2 signaling of CME in CI/RI was investigated. RESULTS: In OGD/R induced in H19-7 cells, CME increased OGD/R-induced cell viability and reduced cell apoptosis, which was reversed by siNrf2 transfection . In MCAO rats, CME improved the neurological deficits and alleviated brain injury. However, co-treatment with MLK385 counteracted these neuroprotective effects of CME on MCAO rats. CONCLUSION: CME could significantly reduce oxidative stress and nerve injury in vitro and in vivo models of CI/RI by regulating the Keap1/Nrf2 pathway.

Clinical independent prognostic factors and overall survival prognostic nomogram for intracranial subependymoma: A SEER population-based analysis 2004-2016.

Purpose: This study was launched to ascertain the independent prognostic factors influencing the overall survival (OS) prognosis of intracranial subependymoma and construct a prognostic model to predict OS time. Materials and methods: We collected data from patients with intracranial subependymoma, including treatment data, follow-up data, and clinical and pathological characteristics from the SEER database within 2004 to 2016, and patients were randomly classified into training and validation cohorts. Univariate and multivariate analyses were applied to the training group through building a Cox proportional hazards model. According to the results of multivariate analysis, we established a nomogram to forecast the OS rate of the per-case patient graphically, then calculated the accuracy of verification in both training and validation cohorts by concordance index (C-index). Univariate and multivariate analyses were used for different subgroups of unoperated versus operated, gross total resection (GTR), subtotal resection (STR), and biopsy after using the propensity score matching (PSM) analyses. Results: A total of 667 patients were enrolled, and we randomly assigned 535 patients (80.21%) into the training cohort and 132 patients (19.79%) into the validation cohort. Age [hazard ratio (HR) = 6.355; 95% confidence interval (CI), 2.240-18.029; p = 0.001] and sex (HR = 0.475; 95% CI, 0.232-0.974; p = 0.042) were the independent prognostic factors in the training cohort. On the basis of age and sex, the nomogram was established to predict the OS for every patient (C-index = 0.733 ± 0.065 in the training cohort and 0.850 ± 0.065 in the validation cohort), and calibration plots reflected the reliability of the nomogram. Age, gender, or laterality was the independent prognostic factor for OS in the different matched subgroups of unoperated versus operated, GTR, STR, and biopsy. Surgical treatment, race, year of diagnosis, insurance, tumor location, tumor size, pathology, tumor grade, and radiation were not statistically significantly different in OS for subependymoma in our research. Conclusion: Age and sex were the independent prognostic variables for OS in intracranial subependymoma. According to our research, we should not be more inclined to choose conservative or surgical treatment. Nonetheless, the information that we present might be useful to suggest potential hypotheses to be tested in the clinical research setting.

Ethanolic Leaf Extract of C. angustifolia Instigates ROS Mediated Apoptosis within Glioblastoma C6 Cells.

Glioblastoma multiforme or GBM is a destructive malignancy of the central nervous system and is accountable for leading cause of cancer related mortality. Inadequate success rate of surgical interventions and development of resistance towards the current therapeutical regime provides impetus for exploring novel therapeutical interventions against the disease. Recently, several epidemiological studies have explored the plausible utility of natural, dietary compounds in influencing the development, progression, and cancer metastasis. Recently, different phytoconstituents of Cassia angustifolia were found to be associated with anti-microbial, anti-cancer and anti-inflammatory effects. Therefore, the aim of the present study was to evaluate the anti-proliferative efficacy of ethanolic leaf extract of C. angustifolia (LCaEt-OH) against rat derived glioblastoma C6 cells. Briefly, the anti-proliferative potential of LCaEt-OH was assessed using MTT assay, quantitative estimation of ROS, and evaluation of mitochondrial membrane potential (ΔΨm). Moreover, the activity of caspases involved in intrinsic apoptotic pathways was also investigated using colorimetric kit followed by quantitative RT-PCR evaluation of modulation in gene expressions triggered due to LCaEt-OH treatment. Treatment of LCaEt-OH on C6 cells elucidated substantial dose-dependent decline in cellular viability. Furthermore, LCaEt-OH showed its efficacy in substantially enhancing intracellular ROS. LCaEt-OH also incited apoptosis in C6 cells by instigating nuclear condensation and dissipation of ΔΨm. In addition, LCaEt-OH mediated instigation of apoptosis was directly influenced by increased activity of caspases indispensable for intrinsic apoptotic pathway. These conclusive evidences indicate towards anticancer efficacy of LCaEt-OH against C6 cells.

Single-Institute Experience of Bypass Surgery for Complex Anterior Cerebral Artery Aneurysms: Paying Special Attention to the Spatial and Diameter Relationship Between the Efferent Arteries.

OBJECTIVE: To present a retrospective review of a single-institute experience with bypass surgery of complex anterior cerebral artery aneurysm. METHODS: Eight patients (5 females and 3 males; mean age, 34.2 years) with complex anterior cerebral artery aneurysms were treated with bypass. There were 3 precommunicating aneurysms, 1 communicating artery aneurysm, and 4 postcommunicating aneurysms (2 in A2 and 2 in A3). A3-A3 side-to-side in situ bypass was performed in 6 cases. A3-radial artery-A3 interpositional bypass was performed in 1 case with A3 segments located far apart, and A3-A3 transplantation was performed in 1 case with nonparallel aligned A3 segments. Of the 8 aneurysms, 3 were secured with proximal clipping, 1 was secured with distal clipping, 1 was secured with direct clipping, 1 was secured with isolation, and 2 were secured with embolization. RESULTS: Aneurysm obliteration was achieved in all cases. Only 1 in situ bypass from a smaller donor artery to a larger recipient artery failed with minor postoperative infarction. Intraoperative bleeding from the site of anastomosis occurred in 1 case during embolization. All patients had complete recovery with normal neurological function during follow-up at outpatient clinics. CONCLUSIONS: We established a simplified surgical algorithm for complex anterior cerebral artery aneurysms based on the geometrical and spatial relationship between efferent arteries. The reasons for bypass failure and hemorrhagic complication were also discussed.

Clinical prognostic factors for central neurocytoma and subgroup analysis of different treatment measures: A SEER database-based retrospective analysis from 2003 to 2019.

Purpose: The study aimed to identify clinical prognostic factors affecting overall survival (OS) in patients with central neurocytoma (CN) and to determine independent prognostic factors in the subgroups of different treatment modalities using a retrospective analysis based on the SEER database from 2003 to 2019. Materials and methods: Data regarding patients with CN, including basic clinical characteristics, treatment measures, and prognosis follow-up, were extracted from the SEER database. The prognostic variables for all patients were assessed using log-rank test as well as univariate and multivariate analyses based on the Cox proportional hazards model. The same statistical methods were used for analysis in different subgroups of gross total resection (GTR), subtotal resection (STR), no surgery, radiotherapy (RT), and no RT. Results: In total, 413 patients were enrolled in this study. Tumor size, primary site surgery, and RT were independent prognostic factors in all patients with CN. In subgroup analyses, RT was not an independent prognostic factor in patients with GTR. However, sex and race were independent prognostic factors in patients with STR. Additionally, tumor size was an independent prognostic factor in patients who did not undergo surgery. Furthermore, sex and primary site were independent prognostic factors in patients who received RT. Size and primary site surgery were independent prognostic factors in patients without RT. Conclusion: In our study, patients with small tumors or GTR or those who did not receive RT showed a better prognosis. GTR was the preferred treatment for CN. RT was not recommended for patients after GTR. Men and African American showed certain advantages after STR surgery. Tumors with a size of >4 cm were recommended for active treatment. In the RT subgroup, patients with tumors outside the ventricle or women had a poorer prognosis than those with tumors within the ventricle or men, respectively. These findings will help clinicians and patients understand the treatment and prognosis of CN visually and intuitively.

Selective Ferroptosis Inhibitor Liproxstatin-1 Attenuates Neurological Deficits and Neuroinflammation After Subarachnoid Hemorrhage.

Ferroptosis is a form of iron-dependent regulated cell death. Evidence of its existence and the effects of its inhibitors on subarachnoid hemorrhage (SAH) is still lacking. In the present study, we found that liproxstatin-1 protected HT22 cells against hemin-induced injury by protecting mitochondrial functions and ameliorating lipid peroxidation. In in vivo experiments, we demonstrated the presence of characteristic shrunken mitochondria in ipsilateral cortical neurons after SAH. Moreover, liproxstatin-1 attenuated the neurological deficits and brain edema, reduced neuronal cell death, and restored the redox equilibrium after SAH. The inhibition of ferroptosis by liproxstatin-1 was associated with the preservation of glutathione peroxidase 4 and the downregulation of acyl-CoA synthetase long-chain family member 4 as well as cyclooxygenase 2. In addition, liproxstatin-1 decreased the activation of microglia and the release of IL-6, IL-1ß, and TNF-α. These data enhance our understanding of cell death after SAH and shed light on future preclinical studies.

Synthesis of 3,4-dihydroquinolin-2(1H)-one derivatives with anticonvulsant activity and their binding to the GABAA receptor.

In this study, a series of 3,4-dihydroquinolin-2(1H)-one derivatives were designed and synthesized using two experimental models, namely maximal electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ), to test the anticonvulsant activity of the target compound in vivo (i.p. in Kunming mice). The neurotoxicity (NT) of the target compound was measured by the rotating rod method (i.p. in Kunming mice). Six compounds with potential activity were selected from the two experimental models to test the 50% effective dose (ED50). In vitro binding experiments with the GABAA receptor were also performed. The results of the pharmacological experiments showed that compound 7-((5-(pentylthio)-1,3,4-oxadiazol-2-yl)methoxy)-3,4-dihydroquinolin-2(1H)-one (5b) showed the best anticonvulsant activity (MES, ED50 = 10.1 mg/kg; scPTZ, ED50 = 9.3 mg/kg), which was superior to activities shown by carbamazepine and ethosuximide, and it also exhibited the most potent binding affinity to GABAA receptors (IC50 = 0.12 µM). The GABA content in Wistar rat brains (i.p.) was also investigated, and the results showed that compound 5b may have a certain effect on the GABA system, as it increased the GABA concentration in the brain of rats. Molecular docking was used to study the binding mode of compound 5b and the GABAA receptor. Compound 5b showed significant interactions with residues at the benzodiazepines binding site on the GABAA receptor. The physicochemical and pharmacokinetic properties of the target compounds were predicted using Discovery Studio 2019 and ChemBioDraw Ultra 14.0.

Severe cerebral edema induced by watershed shift after bypass in a patient with chronic steno-occlusive disease: a case report and short literature review.

BACKGROUND: Carotid occlusive disease is a type of progressive disease resulting in ischemic stroke. Extracranial-intracranial bypass surgery represents a valid therapeutic option when medical treatment does not make effects. The appearance of cerebral edema following bypass is common during acute stage. Additionally, there are many causes of mild cerebral edema, such as hemodynamic changes, venous congestion and others. However, severe edema involving large brain tissue, which presents as reversible aphasia and hemiplegia, remains to be elucidated. CASE PRESENTATION: A 55-year-old man was admitted to the neurosurgery department for repeated dizziness for over a year and sudden onset of syncope 1 month prior, and he was diagnosed with carotid occlusive disease. After surgical contraindications were excluded, dual bypass and encephalo-duro-myo-synangiosis were performed. Although blood pressure and fluid management were strictly under control promptly after surgery, massive cerebral edema involving the left anterior cerebral artery and middle cerebral artery territories occurred from the 6th day after surgery. Additionally, no discernible cerebral infarction or hemorrhage occurred. Moreover, the cerebral blood flow of the middle cerebral artery displayed an early decrease followed by delayed elevation on the left side. Without restricting the spreading of cerebral edema, life-threatening cerebral herniation could develop at any time. Mannitol and furosemide were administered for impending cerebral herniation. The amelioration of symptoms was noticed on the 16th day after surgery. The patient felt relief on the 21st day after surgery. Digital subtraction angiography performed on the 180th day after surgery demonstrated the patency of dual anastomosed vessels, and the patient recovered without any permanent neurological deficit. CONCLUSION: Based on changes in cerebral blood flow and reversible symptoms, the "watershed shift" phenomenon could explain such a severe deficit. However, this deficit was not the same as the classical presentation of the "watershed shift", which involves a moderate amount of brain tissue and presents significant increases in cerebral blood flow. In addition to the "watershed shift", a swollen temporal muscle may also participate in the progression of focal edema.

The order-disorder transition in Cu2Se and medium-range ordering in the high-temperature phase.

The high thermoelectric performance of cuprous selenide (Cu2Se) arises from its specific structures consisting of two independent sublattices, i.e. the rigid face-centered cubic (f.c.c.) Se sublattice and the flexible Cu sublattice showing a variety of ordered configurations at numerous interstitial sites. Upon increasing the temperature, the Cu sublattice undergoes an order-to-disorder transition but the details of the structural evolution have not been fully elucidated. Here, in situ transmission electron microscopy (TEM) is used to investigate the thermally induced structural changes of Cu2Se in both real and reciprocal spaces. Order-disorder transition was found to proceed in nanoblocks accompanied by the structural fluctuations between low-temperature and high-temperature phases. Electron diffraction revealed the emergence of medium-range ordering of Cu atoms in the high-temperature f.c.c. phase. By referring to the Coulomb interaction evaluations, the superstructures for the medium-range ordering were constructed. Such medium-range atomic ordering was sustained over a wide temperature range (from the phase transition temperature to over 800 K in the TEM) but gradually changed to short-range ordering as indicated by the appearance of diffuse scattering rings.

Microglial V-set and immunoglobulin domain-containing 4 protects against ischemic stroke in mice by suppressing TLR4-regulated inflammatory response.

Ischemic stroke is a leading cause of death among human in the world, and a critical cause for long-term disability. Accumulating studies have indicated that inflammatory response regulated by microglia contributes a lot to neuronal death, but the molecular mechanism still remains unclear. V-set and immunoglobulin domain-containing 4 (Vsig4), a complement receptor of the immunoglobulin superfamily (CRIg) that specifically expresses in resting tissue-resident macrophages, plays a critical role in regulating various inflammatory diseases via multiple signaling pathways. However, the effects of Vsig4 on ischemic stroke have not been investigated. In this study, we identified that Vsig4 expression was decreased after cerebral ischemic injury induced by middle cerebral artery occlusion (MCAO). Immunofluorescence staining showed that Vsig4 was co-localized with Iba1 in microglial cells from the infarct region of MCAO-operated mice. After over-expressing Vsig4 in mice, MCAO-induced infarction area and neurological deficits score were markedly attenuated. In addition, neurological dysfunction due to MCAO surgery was improved by Vsig4 over-expression. Microglial M1 polarization was detected in mice with MCAO surgery, which was markedly inhibited by Vsig4 over-expression, as evidenced by the markedly reduced expression of CD16, CD11b, inducible nitric oxide synthase (iNOS) and interleukin 6 (IL-6); however, the expression of M2-like phenotype hallmarks such as arginase 1 (Arg1), CD206, IL-10 and Ym-1 was significantly up-regulated. Mechanistically, the anti-inflammatory role of Vsig4 was mainly through the blockage of toll-like receptor 4/nuclear factor kappa B (TLR4/NF-κB) signaling via the in vivo and in vitro experiments. Also, we found that microglial TLR4 expression in the cerebral infarct area of MCAO mice was highly suppressed by Vsig4 over-expression. In vitro, the neuron-glial mixed culture by fluorescent staining showed that oxygen glucose deprivation (OGD) treatment led to significant cell death, while being attenuated by Vsig4 over-expression in primary microglial cells. Finally, we showed that Vsig4 could interact with TLR4 and repress its expression, subsequently alleviating ischemic stroke. Collectively, our findings demonstrated that microglial Vsig4 protected against post-stroke neuro-inflammation mainly through interacting with TLR4.

Diagnostic performance of DWI for differentiating primary central nervous system lymphoma from glioblastoma: a systematic review and meta-analysis.

OBJECTIVE: The purpose of this meta-analysis was to evaluate the diagnostic performance of diffusion-weighted imaging (DWI) for differentiating primary central nervous system lymphoma (PCNSL) from glioblastoma (GBM). MATERIALS AND METHODS: A thorough search of the databases including PubMed, EMBASE, and Cochrane Library was carried out and the data acquired were up to November 1, 2017. The quality of the studies involved was evaluated using QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies, revised version). Multiple analytic values including sensitivity (SEN), specificity (SPE), positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and the summary receiver operating characteristic (SROC) curve were calculated and pooled for the statistical analysis. The subgroup analysis was also performed to explore the heterogeneity. RESULTS: Eight retrospective studies (461 patients with 461 lesions) were included. The pooled SEN, SPE, PLR, NLR, and DOR with 95% confidence interval (CI) were 0.82 [95% CI 0.70-0.90], 0.84 [95% CI 0.75-0.90], 4.96 [95% CI 3.20-7.69], 0.22 [95% CI 0.13-0.37], and 22.85 [95% CI 10.42-50.11], respectively. The area under the curve (AUC) given by SROC curve was 0.90 [95% CI 0.87-0.92]. The subgroup analysis indicated the slice thickness of the images (> 3 mm versus ≤ 3 mm) was a significant factor affecting the heterogeneity. No existence of significant publication bias was confirmed with Deeks' test. CONCLUSIONS: DWI showed moderate diagnostic performance for differentiating primary central nervous system lymphoma (PCNSL) from glioblastoma (GBM). Moreover, it is of clinical significance using DWI combined with conventional MRI to differentiate PCNSL from GBM.