Search

• Aetiology variated upon the infected region for necrotising fasciitis (NF). • Gram-negative bacteria emerged as a common pathogen for monomicrobial NF. • High Fournier's gangrene (FG) severity index score (greater than 7) was strongly correlated with poor outcomes for FG. • Sepsis at admission was an alarming indicator of poor outcomes for lower extremity NF. In this study, we aimed to illustrate distinctions between Fournier's gangrene (FG) and lower extremity necrotising fasciitis (NF) and screen out possible risk factors of poor prognosis for each cohort. The medical records of qualified patients with NF admitted to the Second People's Hospital of Yibin from January 2016 to June 2021 were retrospectively reviewed. All participants were anatomically categorised into FG and lower extremity NF groups, and their baseline data and microbiological results were compared. Further comparisons of critical parameters were conducted between survivors and nonsurvivors within each group. A total of 49 patients were included in the study with a median age of 58 years, and overall mortality was 20.4%. There were 18 patients with FG and 31 patients with lower extremity NF. A microbiology distinction was found—the predominance of gram-negative infection in FG and gram-positive infection in lower extremity NF. High Fournier's gangrene severity index scores (greater than 7), advanced age, procalcitonin and D-dimer value were identified as risk factors for FG, and the presentation of sepsis was an alarming indicator for lower extremity NF. The distinction of microbiology might provide advice for appropriate antibacterial administrations. In addition, with practical prognostic predicting tools, clinicians might be able to identify patients at increased risk and intervene promptly to avoid unfavourable outcomes. [ABSTRACT FROM AUTHOR]

• A microfluidic evaporator with a photothermal porous layer was designed for continuous sample concentration. • Concentration performance of the evaporator were tested under various operation conditions including light intensity, flow rate and different sample type. • By regulating operation parameters the designed evaporator could reach a maximum concentration factor of 2.9 under continuous working condition with minimum flow/thermal disturbance to the bulk solution. On microfluidic platform, sample concentration plays a crucial role in on-chip detection, analysis and synthesis, etc. Evaporation-induced solvent removal is frequently applied to various application scenarios due to its simplicity and compatibility. However, the enclosed microfluidic channels often hinder the solvent vapor discharge during the evaporation process due to the formation of two-phase flow and interfacial instability. Herein, we propose a novel microfluidic evaporator incorporated with a photothermal porous layer for continuous sample concentration. By absorbing the sample fluid into the porous structure, the evaporator is capable of achieving volumetric heating of the sample fluid thus enhancing the solvent evaporation while the porous network ensured efficient vapor venting. Moreover, the thermal resistance of porous layer shields the heat transfer towards the bulk fluid therefore prevented the sample solution from overheating during the operation process. The results demonstrate the designed microfluidic evaporator exhibits good sample concentration capability under continuous flow conditions. [ABSTRACT FROM AUTHOR]

With the promising potential in non-contact fluid manipulation, the photothermally induced phase change along with the interfacial behaviors have been frequently applied in various microfluidic devices. The property of the working fluid greatly affects the photothermal conversion and thus phase change behaviors. For this reason, the IR laser induced phase change of the NaCl solution in the microchannel was visually studied and compared with distilled water in this work. Experimental results indicated that the NaCl solution exhibited the distinct phase change behaviors. The existence of dissolved ions could weaken the photothermal conversion, leading to lowered temperature rise and evaporation rate as compared to the distilled water. In particular, different from the distilled water, the condensed droplets were formed at the region relatively far away from the evaporating interface due to lower evaporation rate. No coalescence between the condensed droplets and liquid slug was observed. Besides, the effects of the NaCl concentration, laser power and spot position were also investigated. It was found that higher NaCl concentration resulted in lower temperature rise and evaporation rate. With the increase of the input laser power and the decrease of the distance between the laser spot and the interface, the temperature rise and evaporation rate could be improved. The obtained results can be further applied in the design and operation of the microfluidic devices based on the photothermally induced phase change. [ABSTRACT FROM AUTHOR]

In this work, the condensation behaviors of distilled water actuated by photothermal effect of the infrared laser with the wavelength of 1550 nm in a microchannel were investigated through the visualization method and image processing technique. The impacts of the laser power and the laser spot position on the interface movement and slug formation were also explored. It is found that the interface tended to be advanced as a result of the photothermally induced evaporation–condensation–coalescence process at lower laser powers while the interface was firstly advanced at the beginning and then moved backward after the liquid slug formation in front of the interface at high laser powers. Experimental results also showed that higher laser power and smaller distance between the initial gas–liquid interface and fixed laser spot yielded faster advancing of the gas–liquid interface. For cases with the liquid slug formation, the growth rate of the liquid slug increased with increasing the laser power and decreasing the distance of the laser spot position away from the initial interface position as a result of a high evaporation rate. [ABSTRACT FROM AUTHOR]

Streptococcus agalactiae is a contagious pathogen that causes bovine mastitis worldwide, resulting in considerable economic losses. In this study, we isolated 42 S. agalactiae strains in 379 milk samples from cows with subclinical mastitis on 15 dairy farms in 12 Chinese provinces. Analysis based on capsular typing and multilocus sequence typing, combined with patterns of virulence gene scanning and antimicrobial resistance, identified the lineages and populations of the isolates. We grouped the 42 isolates into 7 sequence types belonging to 6 clonal complexes, mainly CC103 (31/42 isolates; 73.8%). We identified an ST-23 strain named Sa 129 for the first time on Chinese dairy farms—this strain is usually associated with human isolates. Capsular types Ia and II were predominant in capsular typing. The prevalence of virulence profile 1 (bibA , cfb , cspA , cylE , fbsA , fbsB , hylB , and pavA) was 64.3%, and represented the main trend in China. With respect to antimicrobial resistance, most isolates were susceptible to β-lactams, rifamycin, glycopeptides, and oxazolidone; resistance to several antimicrobial agents, including lincomycin, clindamycin, and doxycycline, varied in 4 different regions. Our research provides a profile for the molecular epidemiology, multilocus sequence typing, antimicrobial resistance, and virulence gene clustering of S. agalactiae, and may be beneficial for the clinical monitoring, prevention, and control of mastitis in dairy cattle. [ABSTRACT FROM AUTHOR]

• Proposed device produces monodisperse droplets massively, confirmed experimentally. • The device is based on three-dimensional axisymmetric fractal-structure. • The impact of machining deviation on flow rate and droplet size is analyzed. • Obtained relationships: mass-flow, droplets' size deviation and device outlet size. In this paper, a three-dimensional axisymmetric fractal structure device was proposed for massive production of monodisperse droplets. Its channel number could increase to nm for an m -stage fractal device with n -channel distributors. A fractal device with 36 channels was constructed, and the droplet generation experiment was carried out. The experiment showed that the coefficient of variations (CVs) of the generated droplets were all lower than 4.0% at four different flow rates. Additionally, the relationship between the mass flow rate and fractal structure variation was examined through theoretical and data regression analysis. To elaborate the overall structure deviation, the accumulated deviation was introduced, the formula of accumulated deviation and droplet size was given. The results showed that the droplet products were highly monodisperse. The droplet size deviation was within 2% when the accumulated deviation of dispersed- and continuous-phase distributors was less than 4% and 10%, respectively. [ABSTRACT FROM AUTHOR]

In this study, a novel mesoporous CdS/TiO 2 /SBA-15@carbon paper composite membrane was developed to enhance the visible-light responsive CO 2 photoreduction in an optofluidic membrane microreactor. The microscopic morphological and pore volume characterizations indicated that the incorporation of the mesoporous SBA-15 into the membrane development could greatly improve the specific surface area and pore volume. The optofluidic membrane microreactor with the newly-developed composite membrane was evaluated in terms of the methanol concentration and yield. Experimental results showed that the optofluidic membrane microreactor with mesoporous CdS/TiO 2 /SBA-15@carbon paper composite membrane yielded much better performance than did the one without the mesoporous SBA-15. For a given total amount of TiO 2 /SBA-15 in the composite membrane, too high dosage of TiO 2 in the composite membrane caused the reduction in the specific surface area and pore volume, thereby lowering the photocatalytic performance. In addition, it was found that the methanol concentration and yield firstly increased and then decreased with increasing the liquid flow rate. The increase of both the light intensity and NaOH concentration was able to enhance the methanol generation. The obtained results fully demonstrate the superiority of the newly-developed CdS/TiO 2 /SBA-15@carbon paper composite membrane for the CO 2 photoreduction. [ABSTRACT FROM AUTHOR]

[Display omitted] • Chitosan acts as flocculant and carbon source for ABs conversion into bioenergy. • 97.58 % of ABs harvesting was achieved with 0.50 g/L chitosan at pH = 2. • C:N ratio of ABs was improved to 11.82 by using chitosan flocculant. • 70.1 kJ/L of bioenergy was obtained with ABs as feedstocks assisted by chitosan. • Mechanisms of ABs removal and conversion to bioenergy were revealed. Dark fermentation (DF) with notorious algal blooms (ABs) is a promising approach to simultaneously resolve water pollution and energy shortage with extra benefit of carbon neutralization, but it is challenging due to inefficient biomass harvesting and fermentation. To conquer these problems, a strategy using chitosan as dual-functional mediators was proposed, in which ABs were first efficiently harvested with chitosan as flocculant and then fermented into bioenergy with chitosan as C:N regulator. For 1.0 g/L of ABs density, harvesting efficiency of 97.58 % was achieved with 0.50 g/L chitosan dosage under pH of 2. ABs harvesting mechanisms were illuminated from kinetic perspective. More importantly, C:N ratio of the harvest flocs were improved to 11.82 by mixing C-rich chitosan with N -rich algae biomass, which endowed the feedstocks with better property for bioenergy production. As results, the chitosan- microalgae flocs with up-regulated C:N ratio product a higher hydrogen yield of 49.99 mL/(g VS) and improved volatile fatty acids yields with butyric acid (1672.35 mg/L), acetic acid (1170.49 mg/L) and ethanol (361.93 mg/L) as major products. At this time, the highest energy yield of 70.1 kJ/L with an energy conversion efficiency of 59 % was obtained. Together, conversion mechanism of DF indicated that active fatty acids conversion occurred during DF. This study will inspire the eco-friendly ABs disposal with extra benefits of bioenergy production. [ABSTRACT FROM AUTHOR]

In this work, the characteristics of the meniscus evaporation from a microchannel were studied, which was induced by the photothermal effect of the infrared laser with the wavelength of 1550 nm. The evaporation rate and mass transfer coefficient at the interface were determined by the proposed image process technique coupled with an infrared camera. Experimental results showed that once the infrared laser was applied, the interface temperature was rapidly increased but with non-uniform distribution as a result of such a tiny local heating source. Accompanying with the rapid temperature rise, the meniscus evaporation was also immediately actuated. After a certain laser heating period, the interface temperature was increased to a stable value with relatively uniform distribution. In the meantime, the evaporation rate increased and became steady. Besides, the effects of the laser power and laser spot position on the evaporation rate and mass transfer coefficient at the interface were also explored. It was shown that both the interface temperature and evaporation rate linearly increased with the laser power as a result of more heat generated. Smaller distance between the laser spot and front interface yielded higher interface temperature and evaporation rate because of smaller heat transfer resistance resulting from smaller transport length. Reducing the distance could make the increase of the evaporation rate to become more significant. With respect to the mass transfer coefficient, it is interesting to find that the mass transfer coefficients under all cases were almost the same, about 0.4 m/s. [ABSTRACT FROM AUTHOR]

In this paper, chitin was used as raw material to prepare chitin nanowhisker (CNW) by hydrochloric acid hydrolysis. Two hybrid materials, BNSi@CNW and BNPVP@CNW, were prepared by combining modified boron nitride (m-BN) with CNW, in which m-BN was modified with silane coupling agent (APTES) and polyvinylpyrrolidone (PVP) respectively. Polyvinyl alcohol (PVA) and hybrid materials were compounded to prepare PVA composites, respectively, meanwhile the structure and the thermal conductivity of PVA composites were systematically studied. The results show that BNSi@CNW and BNPVP@CNW are evenly dispersed in PVA due to the improved compatibility to enhance the thermal conductivity of PVA composites. The PVA/BNPVP@CNW is further modified by adding hydroxylated carbon nanotubes (CNT) to construct a plane-space thermal conductivity network, further improving the thermal conductivity of composite. Compared with neat-PVA, the thermal conductivity of the PVA composite is increased by 251.6%, and the stable electrical insulation performance is maintained. [Display omitted] [ABSTRACT FROM AUTHOR]