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951.
Rados&#x;aw urowski Pawe&#x; Falkowski Justyna Zygmuntowicz Miko&#x;aj Szafran 《Materials》2021,14(21)
This work focuses on shear thickening fluids (STFs) as ceramic–polymer composites with outstanding protective properties. The investigation aims to determine the influence of raw material parameters on the functional properties of STFs. The following analyses were used to characterize both the raw materials and the STFs: scanning electron microscopy, dynamic light scattering, matrix-assisted laser desorption/ionization time-of-flight, chemical sorption analysis, rheological analysis, and kinetic energy dissipation tests. It was confirmed that the morphology of the solid particles plays a key role in designing the rheological and protective properties of STFs. In the case of irregular silica, shear thickening properties can be obtained from a solid content of 12.5 vol.%. For spherical silica, the limit for achieving shear thickening behavior is 40 vol.%. The viscosity curve analysis allowed for the introduction of a new parameter defining the functional properties of STFs: the technological critical shear rate. The ability of STFs to dissipate kinetic energy was determined using a unique device that allows pure fluids to be tested without prior encapsulation. Because of this, it was possible to observe even slight differences in the protective properties between different STFs, which has not been possible so far. During tests with an energy of 50 J, the dissipation factor was over 96%. 相似文献
952.
The high pavement temperature plays an important role in the development of urban heat island (UHI) in summer. The objective of this study was to develop water retentive and thermal resistant cement concrete (WTCC) to enhance the pavement cooling effects. The WTCC was prepared by combining a water retentive material and a high aluminum refractory aggregate (RA) with porous cement concrete (PCC). Water retention capacity test, fluidity test, and compressive strength test were used to determine the composition ratio of the water retentive material. Mechanical performance and cooling effects of WTCC were evaluated by compressive and flexural strength tests and temperature monitoring test. The mass ratios of fly ash, silica fume, cement, and water in the water retentive material were determined as 65:35:15:63.9. The compressive strength and the flexural strength of WTCC after 28 days curing were 30.4 MPa and 4.6 MPa, respectively. Compared with stone mastic asphalt (SMA) mixture, PCC, and water retentive cement concrete (WCC), surface temperature of WTCC decreased by 11.4 °C, 5.5 °C, and 4.1 °C, respectively, and the internal temperatures of WTCC decreased by 10.3 °C, 6.1 °C, and 4.6 °C, respectively. The water retentive material has benefits of strength improvements and temperature reduction for WTCC. Based on the results, WTCC proved to have superior cooling effects and the potential to efficiently mitigate the UHI effects and be used in medium traffic roads. 相似文献
953.
Naohisa Yoshida Ryohei Hirose Makoto Watanabe Masaski Yamazaki Satoru Hashimoto Shin Matsubara Yu Kasamatsu Naohisa Fujita Rafiz Abdul Rani Osamu Dohi Ken Inoue Yuji Naito Yoshito Itoh 《JGH Open》2021,5(1):160-162
COVID‐19 rarely causes lower gastrointestinal bleeding even though its RNA has been detected in patient's stool. Urgent colonoscopy in a COVID‐19 patient with massive bloody stool requires various procedural and equipment considerations. Here, we present a case of colonoscopic hemostasis of a cecal hemorrhagic ulceration in a patient on heparin for COVID‐19 coagulopathy. We also share various management methods for the prevention of COVID‐19 contamination. A 71‐year‐old man was diagnosed with COVID‐19 pneumonia and subsequently underwent hemodiafiltration. Heparin was initiated for COVID‐19 coagulopathy. At day 42, the patient experienced 2000 mL of bloody stool. An operator performed urgent colonoscopy with three assistants in a negative‐pressure room with full personal protective equipment. A hemorrhagic ulceration was detected at the cecum, and endoscopic hemostasis was performed. Immunohistochemistry was positive for cytomegalovirus. Postprocedure, the endoscopic systems were thoroughly cleaned, and specific measures for endoscope reprocessing and disinfection were performed to prevent contamination with COVID‐19. 相似文献
954.
Robert Jonathon Mane Joanne Jung Eun Choi William Fox Sharpe-Davidson 《Saudi Dental Journal》2021,33(8):842-852
Tramadol is an effective alternative local anaesthetic (LA) agent available in dentistry. This review aims to help guide practice by providing clinicians with relevant data regarding adverse effects (AE) associated with locally administered tramadol in the oral environment. A systematic search of three electronic databases was performed to identify relevant studies reporting AE associated with locally administered tramadol in the oral setting. Selected studies were reviewed and included based on inclusion and exclusion criteria. Data collected included: publication year, study design, participant numbers, adverse effects and follow-up duration. Fifteen articles were included comprising of 547 tramadol participants across eight exodontia and seven non-exodontia studies. Thirty-eight associated AE were reported. Nausea was the most commonly reported (4.6%), followed by dizziness (1.3%), vomiting (0.7%) and local erythema (0.4%). No other AE were reported. The prevalence of total AE was similar in ≥ 50 mg tramadol doses (7.2–7.3%); however the total affected number is not dose dependent. The prevalence of AE and affected participants was less when tramadol was used as a sole LA rather than as an adjunct (5.6% vs. 7.9% and 3.4–5.6% vs. 6.3%, respectively). Thus, tramadol is a safe LA agent with a low prevalence of AE when administered in the dental setting. 相似文献
955.
956.
Ekaterina Silina Victor Stupin Konstantin Koreyba Sergey Bolevich Yulia Suzdaltseva Natalia Manturova 《Pathophysiology》2021,28(3):355
Wound healing is an important medical problem. We evaluated the efficacy of locally administered mesenchymal stem cells (MSCs) isolated from human umbilical cords on the dynamics of skin wound healing. The study was conducted on the backs of Wistar rats, where two square wounds were created by removing all layers of the skin. Four groups were studied in two series of experiments: (1) a Control_NaCl group (the wounds were injected with 0.9% NaCl solution) and a Control_0 group (intact wounds on the opposite side of the same rat’s back); (2) an MSC group (injected MSCs, local effect) and a Control_sc group (intact wounds on the opposite side of the back, remote MSC effect). The area and temperature of the wounds and the microcirculation of the wound edges were measured. Histological and morphometric studies were performed on days 3 and 7 after the wounds were created. The results showed that the injection trauma (Control_NaCl) slowed the regeneration process. In both MSC groups (unlike in either control group), we observed no increase in the area of the wounds; in addition, we observed inhibition of the inflammatory process and improved wound regeneration on days 1–3 in the remote group and days 1–5 in the local (injected) group. The MSC and Control_sc groups demonstrated improved microcirculation and suppression of leukocyte infiltration on day 3. On day 7, all the studied parameters of the wounds of the Control_0 group were the same as those of the wounds that received cell therapy, although in contrast to the results of the Control_ NaCl group, fibroblast proliferation was greater in the MSC and Control_sc groups. The dynamics of the size of the wounds were comparable for both local and remote application of MSCs. Thus, even a one-time application of MSCs was effective during the first 3–5 days after injury due to anti-inflammatory processes, which improved the regeneration process. Remote application of MSC, as opposed to direct injection, is advisable, especially in the case of multiple wounds, since the results were indistinguishable between the groups and injection trauma was shown to slow healing. 相似文献
957.
Folly Patterson Raheleh Miralami Keith E. Tansey Raj K. Prabhu Lauren B. Priddy 《动物模型与实验医学（英文）》2021,4(2):77
Occupational exposure to whole‐body vibration is associated with the development of musculoskeletal, neurological, and other ailments. Low back pain and other spine disorders are prevalent among those exposed to whole‐body vibration in occupational and military settings. Although standards for limiting exposure to whole‐body vibration have been in place for decades, there is a lack of understanding of whole‐body vibration‐associated risks among safety and healthcare professionals. Consequently, disorders associated with whole‐body vibration exposure remain prevalent in the workforce and military. The relationship between whole‐body vibration and low back pain in humans has been established largely through cohort studies, for which vibration inputs that lead to symptoms are rarely, if ever, quantified. This gap in knowledge highlights the need for the development of relevant in vivo, ex vivo, and in vitro models to study such pathologies. The parameters of vibrational stimuli (eg, frequency and direction) play critical roles in such pathologies, but the specific cause‐and‐effect relationships between whole‐body vibration and spinal pathologies remain mostly unknown. This paper provides a summary of whole‐body vibration parameters; reviews in vivo, ex vivo, and in vitro models for spinal pathologies resulting from whole‐body vibration; and offers suggestions to address the gaps in translating injury biomechanics data to inform clinical practice. 相似文献
958.
Bisphenol S (BPS), an analogue of the controversial bisphenol A (BPA) that is found in epoxy resins and plastics, is a potential endocrine-disrupting chemical that can mimic endogenous hormone signaling. However, little is known about the behavioral or immunologic effects of BPS. The purpose of this study was to examine the impact of diets in BPS-treated mice in relation to hyperglycemia, development of type 1 diabetes, immunomodulation, and behavioral changes. Adult male and female nonobese diabetic excluded flora (NODEF) mice were exposed to environmentally relevant doses of BPS (VH, 30, or 300 μg/kg BW) and fed either a soy-based diet, a phytoestrogen-free diet, or a Western diet. NODEF male mice fed a soy-based diet exhibited a decreased curiosity/desire to explore, and possibly increased anxiety-like behavior and decreased short-term memory when exposed to BPS (300 μg/kg BW). In addition, these mice had significant increases in non-fasting blood glucose levels along with increased insulin sensitivity, impaired glucose tolerance, resistance to fasting and proinflammation. Although BPS had little effect on the glucose parameters in NODEF male mice fed a Western diet, there were decreases in %CD24+CD5+ and %B220+CD40L–cell populations and increases in distance traveled during the novel object test, suggesting hyperactivity. NODEF females fed a phytoestrogen-free diet exhibited slight decreases in time spent immobile during the tail suspension test in both the 30 and 300 μg/kg BW dose groups along with increases in %CD4+CD8+ and %Mac3+CD45R+ cell populations, signifying increased hyperactivity and anxiety-like behavior. In conclusion, BPS-exposed NODEF mice exhibited sex and diet-related changes in hyperglycemia, behaviors and immune endpoints. 相似文献
959.
Dulce Parra-Villamar Liliana Blancas-Espinoza Elisa Garcia-Vences Juan Herrera-García Adrian Flores-Romero Alberto Toscano-Zapien Jonathan Vilchis Villa Rodríguez Barrera-Roxana Soria Zavala Karla Antonio Ibarra Raúl Silva-García 《中国神经再生研究》2021,16(7):1273
Several therapies have shown obvious effects on structural conservation contributing to motor functional recovery after spinal cord injury(SCI).Nevertheless, neither strategy has achieved a convincing effect.We purposed a combined therapy of immunomodulatory peptides that individually have shown significant effects on motor functional recovery in rats with SCI.The objective of this study was to investigate the effects of the combined therapy of monocyte locomotion inhibitor factor(MLIF), A91 peptide, and glutathione monoethyl ester(GSH-MEE) on chronic-stage spinal cord injury.Female Sprague-Dawley rats underwent a laminectomy of the T9 vertebra and a moderate contusion.Six groups were included: sham, PBS, MLIF + A91, MLIF + GSH-MEE, A91 + GSH-MEE, and MLIF + A91 + GSH-MEE.Two months after injury, motor functional recovery was evaluated using the open field test.Parenchyma and white matter preservation was evaluated using hematoxylin eosin staining and Luxol Fast Blue staining, respectively.The number of motoneurons in the ventral horn and the number of axonal fibers were determined using hematoxylin eosin staining and immunohistochemistry, respectively.Collagen deposition was evaluated using Masson's trichrome staining.The combined therapy of MLIF, A91, and GSH-MEE greatly contributed to motor functional recovery and preservation of the medullary parenchyma, white matter, motoneurons, and axonal fibres, and reduced the deposition of collagen in the lesioned area.The combined therapy of MLIF, A91, and GSH-MEE preserved spinal cord tissue integrity and promoted motor functional recovery of rats after SCI.This study was approved by the National Commission for Scientific Research on Bioethics and Biosafety of the Instituto Mexicano del Seguro Social under registration number R-2015-785-116(approval date November 30, 2015) and R-2017-3603-33(approval date June 5, 2017). 相似文献
960.
目的探讨改良术式与传统术式治疗腮腺浅叶良性肿瘤的临床效果,以期提高临床治疗水平。方法将苏州大学附属第一医院于2010年1月至2013年2月收治的90例腮腺浅叶良性肿瘤患者依据随机数字表法分为两组:采用传统术式治疗的45例为传统术式组,采用改良术式治疗的45例为改良术式组,用SPSS 13.0统计软件进行统计分析两组治疗后的临床效果。结果改良术式组手术时间、术中出血量、切口长度、解剖面神经分支数均少于传统术式组,差异有统计学意义(P<0.05);改良术式组面瘫、Frey综合征、涎瘘或积涎、耳周皮肤麻木、面部凹陷畸形的发生率均低于传统术式组(P<0.05);两组患者治疗后2周、3个月、12个月在面瘫、面部畸形各分级发生率的比较,差异均有统计学意义(P<0.05)。结论改良术式治疗腮腺浅叶良性肿瘤的临床效果满意,能有效缩短手术时间,减少术中出血,缩短手术时间,并且能降低并发症。 相似文献