An Effective, Economical and Ultra-Fast Method for Hydrophobic Modification of NCC Using Poly(Methylhydrogen)Siloxane

Poor compatibility between nanocellulose crystals (NCCs) and major polymers has limited the application of NCC as bio-reinforcements. In this work, an effective and ultra-fast method was investigated to significantly improve the hydrophobicity of NCC by using poly(methylhydrogen)siloxane (PMHS) as modifier. PMHS possessed amounts of reactive –Si–H groups and hydrophobic –CH3 groups. The former groups were reactive with the hydroxyl groups of NCC, while the latter groups afforded NCC very low surface energy. As the weight ratio of PMHS to NCC was only 0.0005%, the hydrophobicity of NCC was significantly improved by increasing the water contact angle of NCC from 0° to 134°. The effect of weight ratio of PMHS to NCC and the hydrogen content of –Si–H in PMHS on the hydrophobicity and thermal stability was investigated in detail by Fourier transform infrared spectroscopy (FTIR), (X-ray Diffraction) XRD and (thermogravimetric analysis) TGA. The results indicated that PMHS chains were covalently grafted onto NCC and PMHS modification improved the thermal stability of NCC

Remote cerebellar hemorrhage following repeated lumbar punctures

Abstract Background Remote cerebellar hemorrhage (RCH) is a rare complication in neurosurgery. No case of RCH secondary to repeated lumbar punctures (LPs) has been previously reported. Case presentation A 49-year-old man presented with impaired consciousness following persistent fever. Cerebrospinal fluid examination showed high opening pressure, elevated white blood cells, increased protein level, and decreased glucose level, resulting in a diagnosis of bacterial meningoencephalitis. Treatment with repeated LPs and intrathecal injection of ceftriaxone resulted in an improvement in neurological symptoms. However, on day 31 of treatment, brain magnetic resonance image (MRI) showed streaky bleeding in bilateral cerebellum (zebra sign), leading to a diagnosis of RCH. Close observation and repeated brain MRI imaging without specific treatments led to the absorption of bilateral cerebellar hemorrhage, and the patient was discharged with improved neurological symptoms. Repeated brain MRI scans one month after discharge showed that bilateral cerebellar hemorrhage had improved, and had disappeared one year after discharge. Conclusion We reported a rare occurrence of LPs-induced RCH presenting as isolated bilateral inferior cerebellar hemorrhage. Clinicians should be vigilant of the risk factors for RCH, closely monitoring patients' clinical symptoms and neuroimaging findings to determine the need for specialized treatment. Furthermore, this case highlights the importance of ensuring the safety of LPs and managing any potential complications appropriately

Highly Hydrophobic Cotton Fabrics Modified by Poly(methylhydrogen)siloxane and Fluorinated Olefin: Characterization and Applications

Highly hydrophobic cotton fabrics were obtained with poly(methylhydrogen)siloxane (PMHS) and a further fluorinated olefin modification. The chemical structures and microstructures of PMHS-modified cotton fabrics were characterized, and application of the resultant cotton fabrics in stain resistance and oil–water separation was demonstrated. PMHS chains with very low surface energy were grafted onto cotton fabric by the dehydrogenation reaction between –Si–H of PMHS and –OH groups of cotton fabric at room temperature. The water contact angle of PMHS-modified cotton fabric was 141.7°, which provided the modified cotton fabric with good stain resistance to waterborne pollutants. The separation efficiency of diesel from water was higher than 92% for 20 repeatable separation cycles. A further improvement in stain resistance to oil was also demonstrated by a further addition reaction of 1H,1H,2H-perfluoro-1-decene with PMHS-modified cotton fabric

The Cross-Border Transport of PM_2.5 from the Southeast Asian Biomass Burning Emissions and Its Impact on Air Pollution in Yunnan Plateau, Southwest China

Southeast Asia is one of the largest biomass burning (BB) regions in the world, and the air pollutants generated by this BB have an important impact on air pollution in southern China. However, the mechanism of the cross-border transport of BB pollutants to neighboring regions is yet to be understood. Based on the MODIS remote sensing products and conventional observation data of meteorology and the environment, the WRF-Chem and FLEXPART-WRF models were used to simulate a typical PM2.5 pollution episode that occurred during 24–26 March 2017 to analyze the mechanism of cross-border transport of BB pollutants over Yunnan Plateau (YP) in southwest China. During this air pollution episode, in conjunction with the flourishing BB activities over the neighboring Indo-China Peninsula (ICP) regions in Southeast Asia, and driven by the southwesterly winds prevailing from the ICP to YP, the cross-border transport of pollutants was observed along the transport pathway with the lifting plateau topography in YP. Based on the proximity to the BB sources in ICP, YP was divided into a source region (SR) and a receptor region (RR) for the cross-border transport, and the negative and positive correlation coefficients (R) between PM2.5 concentrations and wind speeds, respectively, were presented, indicating the different impacts of BB emissions on the two regions. XSBN and Kunming, the representative SR and RR sites in the border and hinterland of YP, respectively, have distinct mechanisms that enhance PM2.5 concentrations of air pollution. The SR site is mainly affected by the ICP BB emissions with local accumulation in the stagnant meteorological conditions, whereas the RR site is dominated by the regional transport of PM2.5 with strong winds and vertical mixing. It was revealed that the large PM2.5 contributions of ICP BB emissions lift from the lower altitudes in SR to the higher altitudes in RR for the regional transport of PM2.5. Moreover, the contributions of regional transport of PM2.5 decrease with the increase in transport distance, reflecting an important role of transport distance between the source–receptor areas in air pollution change

MicroRNA-34a Attenuates Metastasis and Chemoresistance of Bladder Cancer Cells by Targeting the TCF1/LEF1 Axis

Background/Aims: Chemoresistance is largely responsible for relapses of bladder cancer during clinical therapy. However, the molecular mechanisms involved in the chemoresistance of bladder cancer are unclear. Growing evidence supports the theory that microRNAs (miRNAs) play an important role in chemotherapeutic drug resistance because they are downregulated in many malignancies that have been implicated in the regulation of diverse processes in cancer cells. More specifically, the extent and precise mechanism of the involvement of miR-34as in chemoresistance to epirubicin (EPI) in the treatment of bladder cancer remains unclear. Methods: In this study, real-time quantitative polymerase chain reaction (PCR) was used to analyze the expression of miR-34a in bladder cancer cell line BIU87 and its EPI chemoresistant cell line BIU87/ADR. The miR-34a profiles in bladder cancer tissues were obtained from The Cancer Genome Atlas database. The effect of miR-34a on chemosensitivity was evaluated by cell viability assays, colony formation assays, and in vivo experimentation. Apoptosis and the cell cycle were examined by flow cytometry. A luciferase reporter assay was used to assess the target genes of miR-34a. Western blot and qPCR were used to analyze the expression of target proteins and downstream molecules. Results: The downregulation of miR-34a in bladder cancer serves as an independent predictor of reduced patient survival. The CCK-8 assay showed that miR-34a overexpression resulted in increased sensitivity to EPI, while miR-34a downregulation resulted in chemoresistance to EPI in vitro. Moreover, it was found that miR-34a increased the sensitivity of BIU87/ADR cells to chemotherapy in vivo. The luciferase reporter assay ascertained that TCF1 and LEF1 are direct target genes of miR-34a. It was found that miR-34a increased chemosensitivity in BIU87/ADR cells by inhibiting the TCF1/LEF1 axis. Conclusions: The results of this study indicate that miR-34a contributes to the chemosensitivity of BIU87/ADR by inhibiting the TCF1/LEF1 axis. Consequently, miR-34a is a determinant of BIU87 chemosensitivity and may therefore serve as a potential therapeutic target in bladder cancer treatment

Transplantation Site Affects the Outcomes of Adipose-Derived Stem Cell-Based Therapy for Retinal Degeneration

Adipose-derived stem cells (ASCs) have shown a strong protective effect on retinal degenerative diseases (RDD) after being transplanted into the subretinal space in an animal model. Recently, several clinical trials have been conducted to treat RDD with intravitreal transplantation of stem cells, including ASCs. However, the outcomes of the clinical trials were not satisfactory. To investigate if the transplantation site alters the outcome of stem cell-based therapy for RDD, we isolated rat ASCs (rASCs) and labeled them with green fluorescent protein. Autologous rASCs were grafted into the vitreous chamber or subretinal space in a rat RDD model induced by sodium iodate (SI). The electric response was recorded by ERG. The anatomic structure of the retina was observed in cryosections of rat eyes at posttransplantation weeks 1, 2, and 4. Neural retina apoptosis and epiretinal membrane- (ERM-) like structure formation were investigated by immunostaining. The intravitreal transplantation of rASCs resulted in an extinguished electric response, although the rosette formation and apoptosis of neural retina were reduced. However, the rASCs that grafted in the subretinal space protected the retina from the damage caused by SI, including a partial recovering of the electric response and a reduction in rosette formation. Intravitreally grafted rASCs formed a membrane, resulting in retina folding at the injection site. Müller cells, retinal pigment epithelial cells, and microglial cells migrated from the retina to the rASC-formed membrane and subsequently formed an ERM-like structure. Furthermore, vitreous fluid promoted rASC migration, and rASC-conditioned medium enhanced Müller cell migration as indicated by in vitro studies. These data suggested that the vitreous chamber is not a good transplantation site for ASC-based therapy for RDD and that a deliberate decision should be made before transplantation of stem cells into the vitreous chamber to treat RDD in clinical trials