Search

Bacteria play a central role in the degradation of phytoplankton-derived dissolved organic matter (P-DOM) particularly in algal-blooming aquatic systems; yet our understanding of the interaction between bacteria and P-DOM is still poor. We supplied differential P-DOM that varied in concentration and molecular weight (released from distinct phytoplankton collected from blue-green algal-blooming grass carp Ctenopharyngodon idellus farming ponds) to similar aquatic bacterial communities (isolated from non-blooming grass carp ponds), to explore how P-DOM affects bacterial community dynamics and to identify the most responsive degrading taxa using UV-visible absorption spectroscopy and high-throughput sequencing. Bacterial cultures all had similar degradation effects upon P-DOM, causing decreases in its concentration but increases in its molecular weight and aromaticity. In contrast, bacterial compositional changes varied primarily depending on P-DOM molecular weight, and Bacteroidia taxa were mostly affected, appearing more adapted to metabolize high-molecular-weight P-DOM. Nevertheless, most of the degrading taxa were recurrent and typically members within Gammaproteobacteria and Bacilli, indicating substrate-controlled bacterial responses induced by P-DOM. Network analysis revealed that bacterial communities harbored relatively low-abundant degrading members rather than dominant ones as keystone taxa, which presented simultaneously crucial microbial connections within communities and strong associations with environments and therefore played an over proportional role in maintaining community stability and functioning. Moreover, the keystone taxa may be generalists, and their ecological attributes can be described by oligotrophs that correspond to the K-strategists. Generally, this study implied a pivotal role of Gammaproteobacteria, particularly Pseudomonas, in P-DOM biodegradation, most probably in algal-blooming aquatic environments.

Low back pain (LBP) is an extremely common disorder and is a major cause of disability globally. Intervertebral disc degeneration (IVDD) is the main contributor to LBP. Nevertheless, the specific mechanisms underlying the pathogenesis of IVDD remain unclear. Mitochondria are highly dynamic organelles that continuously undergo fusion and fission, known as mitochondrial dynamics. Accumulating evidence has revealed that aberrantly activated mitochondrial fission leads to mitochondrial fragmentation and dysfunction, which are involved in the development and progression of IVDD. To date, research into mitochondrial dynamics in IVDD is at an early stage. The present narrative review aims to summarize the most recent findings about the role of mitochondrial fission in the pathogenesis of IVDD.

Nanoscale infrared (nano-IR) microscopy enables label-free chemical imaging with a spatial resolution below Abbe's diffraction limit through the integration of atomic force microscopy and infrared radiation. Peak force infrared (PFIR) microscopy is one of the emerging nano-IR methods that provides non-destructive multimodal chemical and mechanical characterization capabilities using a straightforward photothermal signal generation mechanism. PFIR microscopy has been demonstrated to work for a wide range of heterogeneous samples, and it even allows operation in the fluid phase. However, the current PFIR microscope requires customized hardware configuration and software programming for real-time signal acquisition and processing, which creates a high barrier to PFIR implementation. In this communication, we describe a type of lock-in amplifier-based PFIR microscopy that can be assembled with generic, commercially available equipment without special hardware or software programming. We demonstrate this method on soft matters of structured polymer blends and blocks, as well as biological cells of

The mechanical detection of photothermal expansion from infrared (IR) absorption with an atomic force microscope (AFM) bypasses Abbe's diffraction limit, forming the chemical imaging technique of AFM-IR. Here, we develop a Fourier transform AFM-IR technique with peak force infrared microscopy and broadband femtosecond IR pulses. A Michelson interferometer creates a pair of IR pulses with controlled time delays to generate photothermal signals transduced by AFM to form an interferogram. A Fourier transform is performed to recover IR absorption spectra. We demonstrate the Fourier transform AFM-IR microscopy on a polymer blend and hexagonal boron nitride. An intriguing observation is the vertical asymmetry of the interferogram, which suggests the presence of multiphoton absorption processes under the tip-enhancement and femtosecond IR lasers. Our method demonstrates the feasibility of time-domain detection of the AFM-IR signal in the mid-IR regime and paves the way toward multiphoton vibrational spectroscopy at the nanoscale below the diffraction limit.

Refracturing is a promising means to improve the output and estimated ultimate recovery of shale oil and gas resources, which is an efficient method to recover the productivity of low permeability old wells. Refracturing has achieved good results in the development of shale gas wells in North America, and has increased output and decreased the extraction cost significantly of shale gas resources. The disadvantage of unable to control the fracturing fluid accurately of the conventional temporary plugging diverting refracturing technologies like chemical particulates has been exposed in the applications. Wellbore reconstruction technology based on the solid expandable tubular (SET) was studied in this paper, which is a permanent plugging diverting refracturing technology with a high sealing effect and simple operation. Technical principles, tool structures and construction processes were analyzed and relative laboratory tests were conducted to verify the feasibility of this technology. Meanwhile, comparisons between expandable tubular technology and other refracturing technologies were developed to analyze the application prospect in shale oil and gas resources. The indoor tests indicated that wellbore reconstruction technology based on expandable tubular can plug the perforation on the casing effectively with certain sealing pressure, which showed that this technology can realize the wellbore reconstruction to create the wellbore conditions for the next fracturing work. Compared with other temporary plugging refracturing technologies, the expandable tubular technology can achieve accurate control of fracturing fluid and has a better effect of refracturing work. At the same time, it has the advantages of simple operation and big internal diameter compared to other wellbore reconstruction methods like casing plugging technology, which means that bigger displacement can be used and better effect can be achieved in the refracturing work. The conclusions obtained in this paper can promote the development of wellbore reconstruction technology based on expandable tubular, which provides a theoretical reference for the design of the refracturing work in shale oil and gas resources.

Diabetic foot is one of the serious complications of diabetic patients, which makes the society and public health bear a huge economic burden. In recent years, more and more studies at home and abroad have been conducted on the treatment of chronic wounds with autologous platelet-rich fibrin, and the therapeutic concepts and methods have been updated constantly. In this paper, we reviewed the general situation of autologous platelet-rich fibrin, the mechanism of autologous platelet-rich fibrin in promoting the healing of diabetic foot ulcers and the new progress in its application, so as to provide a new strategy for the repair of diabetic foot ulcers.糖尿病足是糖尿病患者严重的并发症之一，给社会和公共卫生系统造成巨大的经济负担。近年来，国内外关于自体富血小板纤维蛋白治疗慢性创面的研究越来越多，治疗理念和方法也不断更新。该文就自体富血小板纤维蛋白的概况、自体富血小板纤维蛋白促进糖尿病足溃疡愈合的机制及应用新进展等进行综述，为糖尿病足溃疡修复提供新策略。.

Aims. For decades now, researchers have been looking for a way to tie the kinematic and dynamic reference frames. Certain worldwide organizations have looked to using co-location in space, combining various techniques. Given the long list of possible applications of the Global Navigation Satellite System (GNSS), it is worthwhile investigating the connection between the most accurate and stable International Celestial Reference Frame (ICRF) and the Earth-centered Celestial Inertial reference frame (ECI) used in GNSS data processing. Methods. We simulated phase-referencing observations of GNSS satellites and nearby radio source calibrators to realize the connection between the two celestial reference frames. We designed two schemes for observation plans. One scheme is to select the satellite target when it can be observed by the greatest number of stations in order to obtain high-precision positioning. During each scan, we employ four regional networks to simultaneously track four chosen satellites. The alternative scheme is to observe satellite orbits of as many satellites as possible on different daily observations. In addition, to test the two schemes, we used Monte Carlo methods to generate 1000 groups of random errors in the simulation. Results. Finally, we estimate the right ascension and declination offsets (∆α, ∆δ) of GNSS satellites in the ICRF, and then derive frame tie parameters based on those results: three global rotation angles (A1, A2, A3). The celestial angular offset results assessed from the former scheme show that this scheme leads to high precision of namely 1 mas, while the parameters of the frame tie determined from the second scheme can achieve an improved precision of better than 1.3 µas.

Atmospheric water vapor plays a key role in Earth's radiation balance and hydrological cycle, and the precipitable-water-vapor (PWV) product under clear-sky conditions has been routinely provided by the advanced Medium Resolution Spectral Imager (MERSI-II) on board Fengyun-3D since 2018. The global evaluation of the PWV product derived from MERSI-II is performed herein by comparing it with PWV from the Integrated Global Radiosonde Archive (IGRA) based on a total of 462 sites (57 219 matchups) during 2018–2021. The monthly averaged PWV from MERSI-II presents a decreasing distribution of PWV from the tropics to the polar regions. In general, a sound consistency exists between PWV values of MERSI-II and IGRA; their correlation coefficient is 0.951, and their root mean squared error (RMSE) is 0.36 cm. The histogram of mean bias (MB) shows that the MB is concentrated around zero and mostly located within the range from −1.00 cm to 0.50 cm. For most sites, PWV is underestimated with the MB between −0.41 and 0.05 cm. However, there is also an overestimated PWV, which is mostly distributed in the area surrounding the Black Sea and the middle of South America. There is a slight underestimation of MERSI-II PWV for all seasons with the MB value below −0.18 cm, with the bias being the largest magnitude in summer. This is probably due to the presence of thin clouds, which weaken the radiation signal observed by the satellite. We also find that there is a larger bias in the Southern Hemisphere, with a large value and significant variation in PWV. The binned error analysis revealed that the MB and RMSE increased with the increasing value of PWV, but there is an overestimation for PWV smaller than 1.0 cm. In addition, there is a higher MB and RMSE with a larger spatial distance between the footprint of the satellite and the IGRA station, and the RMSE ranged from 0.33 to 0.47 cm. There is a notable dependency on solar zenith angle of the deviations between MERSI-II and IGRA PWV products.

The NCCN Guidelines for Squamous Cell Skin Cancer provide recommendations for diagnostic workup, clinical stage, and treatment options for patients with cutaneous squamous cell carcinoma. The NCCN panel meets annually to discuss updates to the guidelines based on comments from panel members and the Institutional Review, as well as submissions from within NCCN and external organizations. These NCCN Guidelines Insights focus on the introduction of a new surgical recommendation terminology (peripheral and deep en face margin assessment), as well as recent updates on topical prophylaxis, immunotherapy for regional and metastatic disease, and radiation therapy.

Summary Surface energy of the underneath interlayer plays a crucial role in determining the morphology of bulk-heterojunction (BHJ) film in solution-processed organic solar cells (OSCs). However, little attention has been paid to this perspective at the microscopic level. In this study, we demonstrate an effective strategy to tune the nanoscale heterogeneous distribution of surface energy (HeD-SE) at interlayers through incorporating two-dimensional (2D) MoS2 nanosheets, which modulate the component distribution, molecular orientation, and phase separation in the upper BHJ layers, leading to suppressed charge recombination and increased charge extraction in devices with enhanced power conversion efficiency (PCE) and device stability. Furthermore, we explore the relationship among the different surface energies of BHJs between the donor and the acceptor, the nanoscale HeD-SE at interlayers, and the PCEs of the resultant devices. This work reveals the impact of nanoscale heterogeneity in the distribution of surface energy in the underneath interlayers on the BHJ morphology and device performance in OSCs.

Ultra-high performance concrete (UHPC) been an advanced concrete introduced as reactive powder concrete (RPC) over twenty years ago, is now being employed for use in the construction industry of some developed countries like China, Germany and United States of America. Its excellent properties in structural performance and durability make it the civil engineering material that will reshape the future of the construction industry in terms of structural performance; and this paper aims at helping construction experts and developing countries to understand and accept UHPC for use in everyday construction works. The paper gives an in-depth review on the classification of UHPCs based on mix proportion and mechanical properties. Firstly, the mixture design and the mechanical properties of UHPC were discussed. Then UHPC was classified into different types based on mechanical properties and the manufacturer’s modification of the ingredients used for reactive powder concrete or multi-scale cement composite production. This review shows that Funk and Dinger model (also known as Modified Andreasen and Andersen model (MAA)) is the most accepted and widely used mix design method for UHPC. It also revealed that UHPC’s compressive strength, tensile strength and flexural strength are in excess of 150, 7 and 40 MPa respectively. It further classified UHPC into BCV®, BSI®, Cemtec®, Ceracem, Ductal, DURA and UHPC with coarse aggregate; and this classification (especially UHPC with coarse aggregate) is a good sign that local materials can be incorporated into UHPC by developing countries for cost minimisation.

Cutaneous squamous cell carcinoma is the second most common cutaneous malignancy with a 5-year disease-specific survival rate of approximately 90%, which decreases dramatically to 50% in the presence of regional lymph node metastases. We sought to examine clinicians’ documentation of pertinent neurological symptoms/signs and lymph node palpation at the time of initial biopsy and treatment using lower lip SCC patients as a cohort. Subsequently, we investigated the correlation between clinical and pathologic SCC features and the aforementioned documentation. A single center, retrospective study of all squamous cell carcinomas of the lower lip biopsied over 10 years was conducted, and univariate models were implemented to correlate the variables. A total of 66 squamous cell carcinomas of the lip in 63 patients were identified. Neurological signs and symptoms were not documented and only three of the tumors were palpated, therefore statistical analysis was not performed. A lymph node exam was documented in 14 of the 63 patients (22%), and statistical analysis showed that among all variables (age, gender, tumor size, tumor stages, tobacco or alcohol use, or history of skin cancer), only the size of the tumor correlated positively with a lymph node examination (RRE 1.15 [95% CI 1.06–1.25], p

Low-temperature, atmospheric pressure plasma presents a new, inexpensive, and environmentally friendly method of water purification. For long duration crewed space missions, a novel water purification system that does not rely on consumable filters and chemicals would be desirable. Plasma systems provide a viable option for these missions, but their operation and designs need to be optimized and compared to existing technology. For this application, gas and power usage are key limiting factors. In this work, water contaminated with methylene blue is purified with plasma. The rate of purification, gas flow usage, and power consumption are compared for multiple devices. A single atmospheric pressure plasma jet is compared with jet array configurations and a novel, 3D printed “plasma sheet” design that expands the size of the plasma surface area. A resource gauge parameter was developed to compare the resource usage and purification rate of each device, and this parameter showed that the plasma sheet was able to improve the rate of purification without increasing resource usage. Additionally, two types of jet arrays were designed that demonstrated the need to exceed a minimum energy and flow rate threshold to maintain effective treatment. A low cost jet was also developed that showed suitable treatment results with a two order of magnitude cost reduction. Finally, a figure of merit was discussed to compare the best performing plasma device with the urine processor assembly used on the International Space Station.

Solution processing of semiconductors is highly promising for the high-throughput production of cost-effective electronics and optoelectronics. Although hybrid perovskites have potential in various device applications, challenges remain in the development of high-quality materials with simultaneously improved processing reproducibility and scalability. Here, we report a liquid medium annealing (LMA) technology that creates a robust chemical environment and constant heating field to modulate crystal growth over the entire film. Our method produces films with high crystallinity, fewer defects, desired stoichiometry, and overall film homogeneity. The resulting perovskite solar cells (PSCs) yield a stabilized power output of 24.04% (certified 23.7%, 0.08 cm2) and maintain 95% of their initial power conversion efficiency (PCE) after 2000 hours of operation. In addition, the 1-cm2 PSCs exhibit a stabilized power output of 23.15% (certified PCE 22.3%) and keep 90% of their initial PCE after 1120 hours of operation, which illustrates their feasibility for scalable fabrication. LMA is less climate dependent and produces devices in-house with negligible performance variance year round. This method thus opens a new and effective avenue to improving the quality of perovskite films and photovoltaic devices in a scalable and reproducible manner.

Plasma-based water purification uses energetic electrons to induce chemical reactions that break down harmful contaminants into benign components. The chemical reactions needed to decompose organic chemicals and bacteria in water are driven by the production of the hydroxyl radical, OH. In this article, an atmospheric pressure plasma jet was used to produce OH and decompose methylene blue (MB) dye in water samples. The behavior of the plasma and the emission of excited OH* near the plasma–liquid interface were analyzed. Nanosecond-resolved measurements near the plasma–water interface were obtained using ICCD imaging and emissions spectroscopy synchronized to the pulsed dc power that drives plasma formation in the plasma jet. The plasma was observed to form along the front of ionization waves as “bullets” that locally produce reactive species. When the bullet hits the water surface, it rebounds and creates a secondary excitation of species at the water surface. The bouncing phenomenon increases the plasma interactions above the water surface and increases OH* excitation up to 192%. However, this increase in excitation and emission does not necessarily mean increased total OH. Higher discharge frequencies produced more OH* emission but did not change the rate of MB dye removal. Higher voltages do increase dye removal rate but with decreasing effectiveness. The results indicate that in steady state, most of the water in the gas channel has been dissociated to form OH, and each bullet merely re-excites the ground state OH (X) into OH* (A) state. A minimum operational frequency of 1 kHz was thus found to provide the best efficiency while maintaining OH production.