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Background: As a chronic inflammatory process, chronic osteomyelitis is caused by bacterial infections that lead to bone destruction. This disease is more common in patients with open fractures and those undergoing multiple surgical procedures after trauma. We aimed to provide a comprehensive overview and critical assessment of the therapeutic efficacy of the anterolateral thigh (ALT) perforator flap in the management of chronic osteomyelitis with dermatologic and soft tissue imperfections localized in the lower extremity. Methods: A retrospective analysis involving a cohort of 16 patients who underwent ALT perforator flap reconstruction for the management of chronic osteomyelitis in the calf region that manifested with integumentary deficiencies was conducted. Results: During the follow-up period spanning from 4 months to 2 years, all 16 patients who underwent ALT perforator flap transplantation exhibited flap viability. Among these cases, 15 patients made a full recovery from the infection and 1 patient had partial survival. Among the 15 cases, 2 patients developed vascular crisis (owing to venous thrombosis during surgical exploration). One patient had a relapse of the disease 1-year post-surgery. The success rate of this surgical method was 15/16, and the surgical complications included flap crisis, flap necrosis, delayed wound healing, and recurrence of infection. Conclusion: The ALT perforator flap, which can cover bone and soft tissues and effectively control infections, can be applied to the treatment of chronic osteomyelitis of the lower limbs with skin defects. Overall, the muscle flap fills the dead space and medullary cavity and skin flap covers the skin defect.

Abstract Hydrothermal carbonization (HTC) has been regarded as a promising technique for turning wet biomass into hydrochar due to its low energy consumption, low exhaust gas emissions, etc. In addition, hydrochar is an important source of dissolved organic matter (DOM), which plays a crucial part in the migration and destiny of pollutants in the environmental medium. However, there are limited studies that focus on the factors that influence the formation of DOM in hydrochar, such as hydrothermal temperature. Therefore, the current study comprehensively characterized the optical properties of DOM within hydrochar derived from sawdust (HDOM) under different hydrothermal temperatures (150–300 °C) by Ultraviolet–visible (UV–Vis) and fluorescence spectroscopy, as well as its complexation characteristic with Cu(II). The findings revealed that the organic carbon content of HDOM reached a peak of 37.3 mg L−1 when the temperature rose to 240 °C and then decreased as the temperature increased. UV–Vis spectroscopy analysis showed that the absorption capacity of HDOM at 275 nm increases with temperature and reaches a maximum value at 240 °C, indicating that high temperature promotes the formation of monocyclic aromatic compounds. High temperature enhances the aromaticity, hydrophobicity, and humification degree of HDOM, thus improving its stability and aromaticity. The E3/E4 ratios are all greater than 3.5, confirming that the main component of HDOM is fulvic acid, which corresponds to 3D-EEM and Pearson's correlation coefficient analysis. The humification index (HIX) of HDOM increased with the rise in hydrothermal temperature (150–240 °C), as observed by the three-dimensional excitation-emission matrix spectroscopy (3D-EEMs). After reaching its peak at 240 °C, the HIX value gradually dropped in line with the trend of the DOC change. Moreover, the bioavailability (BIX) value of DOM was all high and greater than 1, indicating all the HDOM are readily bioavailable. Two microbial humic substances (C1 and C4), a humic-like substance (C2), and a protein-like substance (C3) were discovered in DOM by integrating 3D-EEMs with parallel factor analysis (PARAFAC). Their fluorescence intensity decreases as the Cu(II) concentration increases, indicating the formation of complexes with Cu(II). As the temperature rises, the binding ability of DOM and Cu(II) changes significantly, reaching the optimum at 300 °C. Meanwhile, the substance C2 has the strongest binding ability with Cu(II). This research emphasizes the significance of spectroscopy analysis in determining the evolution of hydrochar-derived DOM, the potential for heavy metal binding and migration, and its characteristics and features. Graphical Abstract

Background: The fingertip amputation is an amputation type of the finger beyond the proximal nail fold. There is no vein available for anastomoses on the dorsal side of the finger, and the palmar vein of the finger is small and tightly attached to the skin. Therefore, it is relatively difficult to implement surgical anastomoses, which poses challenges to the clinical treatment of fingertip amputations. Case report: A 29-year-old male was admitted to the hospital due to “the amputation of the fingertips of the right index, middle, and ring fingers caused by a heavy object compression 3 h ago”. The admission examination revealed that the right index, middle, and ring fingers were completely severed at the 1/2 plane of the nail bed, with irregular sections, severe contusion, and pollution. The X-ray examination showed comminuted fractures of the distal phalanges of the right index, middle, and ring fingers. Based on these findings, the patient was diagnosed with multiple severed fingertips of the right hand (Tamai Zone 1). The patient underwent debridement, vascular exploration, and replantation of the right index, middle, and ring fingertips under emergency general anesthesia. After surgery, anti-inflammatory, spasmolytic, and anticoagulant treatment and regular dressing changes were conducted. The patient did not receive a blood transfusion, and all three fingers survived. The appearance of these fingers was favorable 3 months after surgery, and the flexion and extension of these fingers were normal. Eventually, the patient achieved excellent Chen's hand function scores. Conclusions: To the best of our knowledge, this may be the first successful case regarding the replantation of three fingertips after amputations in Tamai Zone 1 with favorable outcomes. It can be maintained that super microsurgery can be used for the replantation of multiple fingertip amputations.

Summary:. A 26-year-old man was admitted to our hospital due to the replantation of the severed right upper arm and right thigh injury 6 days before. The patient received emergency treatment at a local hospital. He underwent amputation and replantation for the right upper arm and right thigh. After surgery, he experienced fever, limb swelling, and wound pain. At the time of admission to our hospital, the patient exhibited stable vital signs. An infection was found at the replanted wound, and the culture results showed Pseudomonas aeruginosa. After admission, the patient underwent symptomatic antiinflammatory treatment. In addition, he received fracture reduction and external fixation with a bracket, radial nerve exploration and release of the upper and lower limb external fixation with a bracket, upper femur osteotomy, and external fixation with a bracket. He also received reconstruction of elbow flexion functions with biceps femoris tendon transplantation; reconstruction of wrist joint fusion, finger extension function, and palm function; removal of the femoral external fixation with a bracket; and tibiofibular osteotomy and leg lengthening surgery. Moreover, the anterior tibial tendon was fixed to correct foot drop deformity, and the external fixation bracket was removed. Owing to these efforts, the patient achieved limb preservation with well-reconstructed functions.

Summary:. An 80-year-old female patient was admitted to the hospital due to recurrent lymphedema, ulcers, and lymphorrhea in the right lower limb for 7 years. The physical examination revealed changes after the Charles procedure below the right knee joint plane, with a 7 × 7 cm2 lymphorrhea area in the lower one-third plane of the anterior tibia area. Continuous lymphatic exudation and scattered ulcers could be seen. The dorsal artery of the foot could not be reached due to the thickening and fibrosis of the dorsal skin of the foot. The peripheral blood circulation was favorable. The glycated hemoglobin test revealed that blood sugar was not high and could be controlled. The color Doppler ultrasound of lower limb blood vessels revealed no obvious stenosis of arteries, with normal venous return. In addition, no varicose veins or deep venous thrombosis were observed. Based on these findings, the patient was diagnosed with primary lymphedema combined with lymphorrhea after the Charles procedure, complicated with diabetes. After admission, the patient underwent lymphaticovenous anastomosis on the right lower limb under general anesthesia. During the follow-up of 2 months after surgery, it was found that the lymphorrhea was alleviated, the ulcer basically healed, and the swelling on the right lower limb decreased. At the follow-up of 6 months after surgery, the lymphorrhea was eliminated and the ulcer was healed. There were 1-cm reduction in leg and back circumference and 10% volume reduction. The lymphedema quality-of-life score of this patient was 57 points after surgery.

A risk-aware scheduling method of multienergy virtual power plant (MEVPP) is proposed to measure the uncertainty in MEVPP. First, a novel day-ahead uncertainty scenario generation method based on denoising diffusion probabilistic model is proposed, and historical data are employed to learn the error relationship between real power curves and predict power curves. The probability distribution of the prediction error which describes the day-ahead output power curve of renewable energy source is learned by parameter training. Subsequently, the effect of risk aversion on decision-making is investigated by implementing conditional value-at-risk in the optimization model, MEVPP operation mode under the carbon trading and green certificate trading mechanism is analyzed. Finally, the proposed scheme is implemented on a test MEVPP with carbon trading, and green certificate trading is addressed in detail through a numerical study. Moreover, the effects of the operator’s risk-averse behavior on the MEVPP are investigated.

Summary:. A 50-year-old man was admitted to the hospital with a chief complaint of long-standing cold-induced numbness in the fingers for more than a year, accompanied by persistent hand pain and fingertip ulceration for 3 months. On physical examination, radial and ulnar artery pulsation was absent in both limbs, and pale skin color, low skin temperature, and limited finger range of motion were noted. Gangrene was detected in the fingertips of the left index and middle fingers, and the right middle and ring fingers. The patient was diagnosed with bilateral arterial occlusion and vibration white finger. Upon admission, the patient underwent an intervention surgery on the right side. Subsequently, transplantation of the descending branches of the left and right lateral femoral circumflex arteries was performed to restore blood flow in the bilateral radial arteries. Additionally, debridement was conducted without shortening after the surgical procedure, the patient received anticoagulation, anti-inflammatory, and symptomatic treatment. The bilateral finger skin temperature increased by 3 °C postoperatively, and the accompanying pain and numbness were alleviated. The wound healed 1 month after surgery, and no recurrence of pain or ulcer was reported during the 1-year follow-up period. Eventually, his hand function recovered, without any impact on the vascular donor site.

ObjectiveThis paper aims to investigate the complex influence of environmental disturbances on unmanned surface vehicles (USVs) under real ocean conditions, and control USVs to overcome disturbances and realize path following. MethodsAn improved active disturbance rejection controller (ADRC) based on the model-free adaptive control (MFAC) law (ADRC−MFAC) is proposed to establish the non-linear relationship between the input data (rudder angle) and output data (heading angle, angular velocity), and identify the unknown disturbances of the system. In this way, stable heading control can be achieved. Combined with the adaptive line-of-sight (LOS) guidance law, it achieves accurate tracking control through dynamic heading control.ResultsThe simulation results show that the controller can control USVs to approach the preset path quickly and achieve a desirable tracking control effect under complex disturbances. ConclusionThe research results do not depend on the specific model of USV and can provide valuable references for ship tracking control.

Retrieval of four finger injury at proximal stump amputation with segmental injury along with soft tissue defect and impending compartment syndrome continues to be challenge for the surgeon. Immediate transplant considering temporary ectopic foster as a practical option in special case. We describe temporary ectopic finger implant for crush injury at Metacarpophalangeal (MCP level) with hand torsion along with forearm compartment was fostered to Dorsum of the foot. The torsion fingers was temporary fixed with mini external fixator for stabilization as salvage, ALT free flap was used to cover soft tissue defect of the hand. Replantation of survived figure was performed using the long pedicle to anatomical site without crushing the MCP joint to allow for later tendon transfer for finger. Satisfactory function regained with no foster site (foot) complication like pain or disability. The author validated ectopic foster for amputee as and procedure of choice for salvage of extremity under special circumstances.

AbstractThe detailed, high-resolution images captured by drones pose challenges to target detection algorithms with complex scenes and small-sized targets. Moreover, targets in unmanned aerial vehicle images are usually affected by factors such as viewing perspective, occlusion, and light, which increase the difficulty of target detection. In response to the above issues, we propose an improved SDMSEAF-YOLOv8 for target detection based on YOLOv8, combined with a Bi-directional Feature Pyramid Network, to improve the sensing ability of the model for multiscale targets. A Space-to-depth layer replaces the traditional strided convolution layer to enhance the extraction of fine-grained information and small-sized target features. A Multi-Separated and Enhancement Attention module enhances the feature learning ability of the occluded target region, thus reducing missed and false detections. Four detection heads are employed for tiny target detection, each responsible for different size ranges, so as to improve the accuracy and robustness of small target detection. The conventional non-maximum suppression algorithm is improved, so as to reduce the problem of missed detections under a densely occluded scene by setting the attenuation function to adjust the confidence of the treated box based on the overlap between it and the highest-scoring box. Experiments demonstrate that the accuracy of SDMSEAF-YOLOv8 exceeds that of state-of-the-art models on the VisDrone2019-DET-val dataset, with a mAP of 42.9% at 640-pixel resolution, 14.8% over the baseline YOLOv8-x algorithm model, and 6.0% over the known state-of-the-art Fine-Grained Target Focusing Network model and with twice as fast detection.

Microwave absorbing materials (MAMs) are materials that effectively absorb incident electromagnetic (EM) wave energy, reducing reflection and scattering. They play a crucial role in enhancing electronic reliability, healthcare, and defense security. However, traditional MAMs like ferrites, magnetic metals, and polymers possess certain limitations, including low impedance matching, narrow absorption bandwidth, poor chemical stability, and high filling ratio, which hinder their further development. To address the requirements of lightweight, wideband, and high‐efficiency absorption, precise structural design has emerged as a captivating research focus. Additionally, comprehending the structure–property relationships between these unique microstructures and EM response and loss mechanisms still poses significant challenges. Herein, a comprehensive review of MAMs is presented with varied structural designs encompassing various scales, providing a detailed introduction of the relationship between various potential structural designs of MAMs and their corresponding EM characteristics and loss mechanisms. Moreover, EM theoretical calculation models, characterization, and analysis methods are discussed. Finally, the article proposes the challenges and prospects for the development of structural design EM wave absorbers.

Summary: Recently, the design of graphene-based films with elaborately controlled microstructures and optimized electromagnetic interference shielding (EMI) properties can effectively improve EM energy attenuation and conversion. Herein, inspired by the structure of multi-layer steamed bread, an alternating multilayered structure with polyvinyl alcohol (PVA)-derived carbon layers and graphene/electrospun carbon nanofibers layers was designed through alternating vacuum-assisted filtration method. The composite film exhibited favorable impedance matching, abundant loss mechanism, and excellent EMI shielding ability, resulting in absorption dominated shielding characteristic. Thus, the resultant 7-layer alternating composite films with a thickness of 160 μm achieved an EMI shielding effectiveness (EMI SE) of up to 80 dB in the X-band. Specially, finite element analysis was applied to demonstrate the importance of seven-layer film alternations and detailed analysis of electromagnetic shielding mechanisms. Taken together, this effort opens a creative avenue for designing and constructing flexible composite films with excellent EMI shielding performance.

Summary:. Necrotizing soft tissue infection (NSTI) is a complex infection known for its rapid progression of necrosis within the subcutaneous tissue and fascia. Time is of essence for the management of NSTI. In this report, we present a case of NSTI after infection of poorly managed diabetic foot ulcer in the ankle. The limb salvage approach involves sequential staged procedures. Multiple surgical debridements and “washout” were performed for source control. At the same time, the patient also received a systemic antibiotic regimen. In the second stage, a perforator free flap taken from the anterolateral thigh was used to repair the extensive soft tissue defect and reconstruct a functional foot to achieve maximal limb salvage. The kickstand technique of external fixation was used to reduce soft tissue compression and enhance the surgical offloading of the skin flap. At the 2-year follow-up, the skin integrity of the flap was well-preserved, and the patient returned to his premorbid quality of life.

The transient electromagnetic (TEM) method has long been applied in tunnel advanced prediction. However, it remains questionable to what extent a geologic anomaly body will influence the induced electromagnetic response in front of the heading face. The dilemma is partly because observed TEM data are frequently interpreted by empirical formulas or proportional relationships, and a quantitative measurement has not been established. In this paper, we strive to understand the TEM characteristics from a 3D finite-element time-domain (FETD) modeling aspect. The modeling algorithm is based on unstructured space meshing and unconditional stable time discretization, which ensures its accuracy and stability. The modeling algorithm is verified by a half-space model, in which the misfit of late-time channels that we are concerned with is generally below 1%. The algorithm has also been utilized to carry out the TEM response of tunnel models with different types of TEM devices. Through model studies, we find that both the traditional central-loop device and the recently developed weak-coupling opposing-coil device are feasible in tunnel advanced detection. Nevertheless, the latter type of device better distinguishes low-resistivity anomalies at 30 m ahead of the heading face with a relative difference (between models with and without the anomaly) of more than 1000% at certain time channels, compared with only a 10% difference of the central-loop device. Also, we conclude that the vertical electromagnetic field component should be recorded and interpreted together with the horizontal field to provide more convincing results.

A novel intelligent hybrid model is proposed in this paper for accurate prediction and modeling of solar power plants using the wavelet transform package (WTP) and generative adversarial networks (GANs). In the proposed model, the wavelet transform is deployed for decomposing the solar energy signal into the sub-harmonics followed by the statistical feature selection analyses. The GAN model as a deep learning approach is proposed for learning each sub-frequency and predicting the future of the solar energy in the short-time window. Due to the high complexity of the solar irradiance data when training, an evolutionary algorithm based on dragonfly algorithm (DA) is suggested to train the generative and discriminator networks in the GAN. Moreover, a three-phase adaptive modification is suggested to enhance the search capabilities of the DA optimization. The efficiency and appropriate performance of the proposed model is examined and compared with the most successful models such as artificial neural networks (ANNs), support vector machine (SVM), time series, auto-regressive moving average (ARMA), and original GAN on several benchmarks for varied forecast time horizons. The simulation results on the datasets of two regions show the mean absolute percentage error (MAPE) of 0.0282 and 0.0262, when 1-pace forecast horizon, for the two regions which increase up to 0.0531 and 0.0631 for 6-pace forecast horizon. Moreover, the root mean absolute error (RMSE) is 0.0473 and 0.0479 for the two regions at 1-pace forecast horizon which increased up to 0.0895 and 0.0946 for 6-pace forecast horizon. These results show the more precise performance of the proposed forecast deep learning as well as the more optimal performance of the modified DA over the other algorithms shown in the results.

Cobalt oxide (CoO) nanosheets with a size of about 2.7 nm are prepared. The proper annealing temperatures (200 °C–400 °C) are used to control the conversion of CoO nanosheets to high-ratio hexagonal phases from high-ratio cubic phases at room temperature. The analysis revealed the hexagonal phase is preferable to cubic phase for oxygen evolution reaction of CoO nanosheets. The ultrafine CoO nanosheets with high-ratio hexagonal phases showed a particularly high mass activity of 5597Ag−1 at 1.615 V, 22.8 times higher than that of the noble metal Ru cluster electrocatalyst. Our study indicates an effective way to synthesize nanosheet catalysts with high mass activity.

Critical heat flux (CHF) determines the safety and application of pool boiling heat transfer in many industrial fields. The influence of saturation pressure and surface roughness on saturated pool boiling CHF in hydrofluoroether HFE-7100 was experimentally studied in this investigation. Visualization and heat transfer measurements were conducted at the critical and transition boiling state, and further, the accuracy of CHF prediction models and enhancement mechanism had been analyzed. The polished boiling surfaces had various surface roughness values ranging from 0.019 to 0.587 μm and their contact angles varied from 7° to 10°, while the experimental saturation pressure changed from 0.7 to 2.0 bar. The visual images showed that the pool boiling phenomenon at a critical state was composed of different-sized bubbles, vapor column, and large mushroom vapor, whereas the unsteady blanket of vapor continually injected bubbles at a transition state. The saturation pressure and surface roughness had an obvious improvement on pool boiling CHF, which might be ascribed to the effects of bubble momentum owing to evaporation, distribution and recovery period of a heat transfer boundary layer, capillary action of the working liquid, as well as ratio of vapor jets’ area. Compared with the well-known correlations reported in the literature, CHF correlation of Bailey et al. (2006) predicted the current results more accurately. To further improve the prediction accuracy, a new empirical correlation for CHF dimensionless K considering the effects of saturation pressure and surface roughness was developed, and the predicted values were in better agreement with the experimental data.

The development and utilization of biomass can not only address the demand for low-carbon energy and reduce environmental pollution, but can also facilitate the achievement of carbon neutrality. However, there are many factors justifying the case for low utilization of agricultural residues. These factors could be well controlled by producing top-quality pellets. Production of pellets is generally accompanied by the problems of high energy consumption and serious mold wearing. To eliminate these deficiencies, pretreatment has attracted scholars’ attention. In this review, the effects of four pretreatments on the properties of pellets were assessed. Thermal pretreatment can improve the hydrophobicity of pellets, and optimize their properties, while degradation of diverse extractives is noteworthy. Hydrothermal pretreatment improves the physical properties of pellets, through the increase of polar functional groups on the surface of the biomass. Ultrasonic vibration-assisted (UV-A) pelleting produces pellets under low pressure without a heating process; however, it is still not applied to large-scale production. Supercritical fluid extraction can achieve the graded utilization of extracts and bioactive substances in biomass, and the residues can be subsequently utilized as pellet feedstock. Mild hydrothermal treatment is a promising approach to improving the quality of agricultural pellets. Additionally, the effects of process parameters on the physical and chemical properties of pellets should be systematically analyzed.

The precise prediction of coal seam thickness in operating mines is crucial for the construction of transparent mines. Geological borehole data or a small amount of seismic information is frequently used in traditional coal seam thickness prediction methods; however, these methods have poor precision. In this study, we introduced a model for predicting coal seam thickness based on the comprehensive preference for seismic attribute combination (CPSAC) and the least squares support vector machine (LS-SVM) optimized by the whale optimization algorithm (WOA). We used the CPSAC to modify the mass disturbed data in the seismic attribute data to predict the coal seam thickness. To achieve this the sample size was reduced by optimizing the seismic attribute combinations, and the modified attribute data was entered into the LS-SVM., Furthermore, to create an accurate prediction model for coal thickness, we employed the WOA to determine the optimal penalty coefficient and kernel coefficient of the LS-SVM. An empirical case study was conducted in the northeast mining area of the ZJ mine in the Huainan coalfield. The coal thickness of two mining faces in this research area were estimated and compared, demonstrating the proposed method’s high prediction accuracy. The proposed method has guiding implications for developing an accurate mining geological model and facilitating the accurate use of coal resources.

Abstract High‐performance microwave absorbers with special features are desired to meet the requirements of more complex modern service environments, especially corrosive environments. Therefore, high‐efficiency microwave absorbers with corrosion resistance should be developed urgently. Herein, a 3D NiAl‐layered double hydroxide/graphene (NiAl‐LDH/G) composite synthesized by atomic‐layer‐deposition‐assisted in situ growth is presented as an anticorrosive microwave absorber. The content of NiAl‐LDH in the composite is optimized to achieve impedance matching. Furthermore, under the cooperative effects of the interface polarization loss, conduction loss, and 3D porous sandwich‐like structure, the optimal NiAl‐LDH/G shows excellent microwave absorption performance with a minimum reflection loss of −41.5 dB and a maximum effective absorption bandwidth of 4.4 GHz at a loading of only 7 wt% in epoxy. Remarkably, the encapsulation effect of NiAl‐LDH can restrain the galvanic corrosion owing to graphene. The epoxy coating with the NiAl‐LDH/G microwave absorber on carbon steel exhibits long‐term corrosion resistance, owing to the synergetic effect of the superior impermeability of graphene and the chloridion‐capture capacity of the NiAl‐LDH. The NiAl‐LDH/G composite is a promising anticorrosive microwave absorber, and the findings of this study may motivate the development of functional microwave absorbers that meet the demands of anticorrosive performance of coatings.

Helical carbon nanotubes (HCNTs) were functionalized to fabricate HCNT/epoxy composites. Acid oxidation and a silane coupling agent, glycidoxypropyltrimethoxysilane (KH560), were used to modify the HCNTs. Remarkably, the flexural strength and the flexural strain were enhanced by 72.0% and 325.0%, respectively, compared to pure epoxy after adding a small amount of the KH560 modified HCNTs (K-HCNTs). Simultaneously, the tensile strength and Young’s modulus of K-HCNTs/epoxy composites were 51.3% and 270.9% higher than those of pure epoxy. It is found that the presence of silane molecules improved the dispersion of HCNTs in epoxy and the interfacial interaction. Moreover, it has been found that the mechanically interlocking effect from the helical shape of HCNTs also contributes to the improved mechanical properties of epoxy composites, compared to their straight multi-walled carbon nanotube (MWCNT) counterparts. This work provides a low-cost and efficient approach to strengthen and toughen epoxy composites.

Antibiotic resistance is currently a major global public health issue. In particular, the emergence and transfer of antibiotic resistance genes (ARGs) is a matter of primary concern. This study presented a method for ruling out the transfer of naked DNA (plasmid RP4 lysed from donor cells) during the cell-to-cell conjugation, using a modified “U-tube”. A series of gene transfer assays was conducted in both flask and modified U-tube, using Pseudomonas putida KT2440 (P. putida (RP4)) harboring the RP4 plasmid as the donor strain, Escherichia coli (E. coli, ATCC 25922) in pure culture as sole recipient, and bacteria from reclaimed water microcosms as multi-recipients. The verification experiments showed that the U-tube device could prevent direct contact of bacteria without affecting the exchange of free plasmid. In the experiments involving a sole recipient, the transconjugants were obtained in flask samples, but not in modified U-tube. Furthermore, in experiments involving multi-recipients, transfer of naked DNA in the modified U-tube accounted for 5.18% in the transfer frequency of the flask transfer experiment. The modified U-tube proved to be useful for monitoring the interference of naked DNA in the research of conjugative transfer and calculating the exact conjugative transfer rate. This device is identified as a promising candidate for distinguishing different gene transfers in practical application because of its convenient use and easy and simple manufacture.

In this paper, spherical carbon dots (CDs) with distinct compositions and surface states have been successfully synthesized by a facile microwave method. From the fluorescence spectra, several characteristic luminescence features have been observed: surface amino groups are dominant in the whole emission spectra centering at 445 nm, and the fingerprint emissions relevant to the impurity levels formed by some groups related to C and N elements, including C-C/C=C (intrinsic C), C-N (graphitic N), N-containing heterocycles (pyridine N) and C=O groups, are located around 305 nm, 355 nm, 410 nm, and 500 nm, respectively. Those fine luminescence features could be ascribed to the electron transition among various trapping states within the band structure caused by different chemical bonds in carbon cores, or functional groups attached to the CDs’ surfaces. According to the theoretical calculations and experimental results, a scheme of the band structure has been proposed to describe the positions of those trapping states within the band gap. Additionally, it has also been observed that the emission of CDs is sensitive to the concentration of Fe3+ ions with a linear relation in the range of Fe3+ concentration from 12.5 to 250 μM.

Polycrystalline ZnO thin films are prepared by the co-sputtering method under different oxygen partial pressures. Films deposited in pure argon gas exhibit ferromagnetism, whereas other films deposited under different oxygen partial pressures are diamagnetism. XPS results show the presence of Zn interstitial and oxygen vacancy in all of samples. Further analysis indicates that Zn interstitial may play an important role in triggering magnetic order on the undoped ZnO thin films by inducing an alteration of electronic configuration.

A significant amount of wastewater has been produced from the oilfield extractive fluid with the development of oilfields in recent decades. Settling is the first process in the treatment of oilfield wastewater. As one of the most crucial devices in oilfield wastewater treatment, the vertical sedimentation tank has been widely utilized in the precipitation process. This work aims to explore the properties of vertical sedimentation tanks for oil-water separation and analyze related variables in the separation. First, we utilize the for-profit software Fluent for computational fluid dynamics, in which the RNG k-ε model, the multiphase flow mixing model, and the PBM model are used to simulate the internal flow field distribution in the vertical sedimentation tank under various boundary conditions. Then, the implication of changing the boundary conditions on the vertical sedimentation tanks is analyzed. It is demonstrated that by replacing the PBM model for the homogeneous particle size, the simulation of oil-water two-phase flow in sedimentation tanks is more correctly measured. The findings demonstrate that raising the operating temperature increases the oil content at the output and dewatering rate of the sedimentation tanks by 73.1%; however, above 44°C, the effect of oil removal gradually tends to deteriorate; the longer hydraulic retention time within the 8-h range, the better the effect of oil-water separation, with the best effect occurring at 8 h; and the more viscous the oil phase, the more resistance of the oil droplets to float, increasing the water phase oil-carrying capacity, resulting in a 36.5% reduction in oil content at the outlet and dewatering rate of the settling tanks. The simulation in this paper can provide theoretical direction and conference for the design of vertical sedimentation tanks, as well as improve the performance of oily wastewater treatment facilities. [ABSTRACT FROM AUTHOR]