Hydrothermal and Laser-Guided Janus Membrane with Dual Wettability for Unidirectional Oil/Water Separation

The development of a Janus membrane with contrasting chemical functionality/or wettability on opposite faces has shown great promise as a passive and energy-efficient oil/water separation technology. Notably, one side of the membrane is designed hydrophilic (i.e., water-attracting in air and underwater oleophobic) and the other hydrophobic (i.e., water-repelling in air and underwater oleophilic). The distinctive surface wettability features of the membrane allow it to repel water and attract oil without consuming energy, thus making it an attractive technology for passively separating oil/water mixtures. The hydrophobic face of the membrane captures oil droplets while allowing water to pass through, and the hydrophilic side attracts water droplets and allows oil to pass. Nonetheless, crafting a Janus membrane is complex, tedious, and expensive. To overcome these limitations, an easy and inexpensive two-step fabrication process for the Janus membrane is proposed in this work. The first step involves creating a superhydrophilic face by the hydrothermally guided deposition of nanoneedles on either side of a commercially available hydrophobic carbon sheet. In the second step, the double-faced surface is subjected to a pulsed laser to create conical micropores studied for oil/water separation. The fabricated membrane is economically affordable and environment friendly. Besides being energy-efficient (as the separation process works passively), the membrane demonstrates an efficient oil/water separating performance. The potential application of this work is diverse and impactful, encompassing wastewater treatment, oil spill cleanup, and various industrial separation processes.

On-Chip Liquid Manipulation via a Flexible Dual-Layered Channel Possessing Hydrophilic/Hydrophobic Dichotomy

The hydrophilic/hydrophobic cooperative interface provides a smart platform to control liquid distribution and delivery. Through the fusion of flexibility and complex structure, we present a manipulable, open, and dual-layered liquid channel (MODLC) for on-demand mechanical control of fluid delivery. Driven by anisotropic Laplace pressure, the mechano-controllable asymmetric channel of MODLC can propel the directional slipping of liquid located between the paired tracks. Upon a single press, the longest transport distance can reach 10 cm with an average speed of ∼3 cm/s. The liquid on the MODLC can be immediately manipulated by pressing or dragging processes, and versatile liquid-manipulating processes on hierarchical MODLC chips have been achieved, including remote droplet magneto-control, continuous liquid distributor, and gas-producing chip. The flexible hydrophilic/hydrophobic interface and its assembly can extend the function and applications of the wettability-patterned interface, which should update our understanding of complex systems for sophisticated liquid transport.

Design and Manufacture of an Optimised Side-Shifted PPM EMAT Array for Use in Mobile Robotic Localisation

Guided wave Electro Magnetic Acoustic Transducers (EMATs) offer an elegant method for structural inspection and localisation relative to geometric features, such as welds. This paper presents a Lorentz force EMAT construction framework, where a numerical model has been developed for optimising Printed Circuit Board (PCB) coil parameters as well as a methodology for optimising magnet array parameters to a user's needs. This framework was validated experimentally to show its effectiveness through comparison to an industry built EMAT. The framework was then used to design and manufacture a Side-Shifted Unidirectional Periodic Permanent Magnet (PPM) EMAT for use on a mobile robotic system, which uses guided waves for ranging to build internal maps of a given subject, identifying welded sections, defects and other structural elements. The unidirectional transducer setup was shown to operate in simulation and was then manufactured to compare to the bidirectional transmitter and two-receiver configurations on a localisation system. The unidirectional setup was shown to have clear benefits over the bidirectional setup for mapping an unknown environment using guided waves as there were no dead spots of mapping where signal direction could not be interpreted. Additionally, overall package size was significantly reduced, which in turn allows more measurements to be taken within confined spaces and increases robotic crawler mobility.

Wafer-Scale Epitaxial Growth of Unidirectional WS2 Monolayers on Sapphire

Realization of wafer-scale single-crystal films of transition metal dichalcogenides (TMDs) such as WS₂ requires epitaxial growth and coalescence of oriented domains to form a continuous monolayer. The domains must be oriented in the same crystallographic direction on the substrate to inhibit the formation of inversion domain boundaries (IDBs), which are a common feature of layered chalcogenides. Here we demonstrate fully coalesced unidirectional WS₂ monolayers on 2 in. diameter c-plane sapphire by metalorganic chemical vapor deposition using a multistep growth process to achieve epitaxial WS₂ monolayers with low in-plane rotational twist (0.09°). Transmission electron microscopy analysis reveals that the WS₂ monolayers are largely free of IDBs but instead have translational boundaries that arise when WS₂ domains with slightly offset lattices merge together. By regulating the monolayer growth rate, the density of translational boundaries and bilayer coverage were significantly reduced. The unidirectional orientation of domains is attributed to the presence of steps on the sapphire surface coupled with growth conditions that promote surface diffusion, lateral domain growth, and coalescence while preserving the aligned domain structure. The transferred WS₂ monolayers show neutral and charged exciton emission at 80 K with negligible defect-related luminescence. Back-gated WS₂ field effect transistors exhibited an I_ON/_OFF of ∼10⁷ and mobility of 16 cm²/(V s). The results demonstrate the potential of achieving wafer-scale TMD monolayers free of inversion domains with properties approaching those of exfoliated flakes.

Antibuoyancy and Unidirectional Gas Evolution by Janus Electrodes with Asymmetric Wettability

The bubbles electrochemically generated by gas evolution reactions are commonly driven off the electrode by buoyancy, a weak force used to overcome bubble adhesion barriers, leading to low gas-transporting efficiency. Herein, a Janus electrode with asymmetric wettability has been prepared by modifying two sides of a porous stainless-steel mesh electrode, with superhydrophobic polytetrafluoroethylene (PTFE) and Pt/C (or Ir/C) catalyst with well-balanced hydrophobicity, respectively, affording unidirectional transportation of as-formed gaseous hydrogen and oxygen from the catalyst side to the gas-collecting side during water splitting. "Bubble-free" electrolysis was realized while "floating" the Janus electrode on the electrolyte. Antibuoyancy through-mesh bubble transportation was observed while immersing the electrode with the PTFE side downward. The wettability gradient within the electrode endowed sticky states of bubbles on the catalyst side, resulting in efficient bubble-free gas transportation with 15-fold higher current density than submerged states.

Feasibility and yield of screening for diabetes mellitus among tuberculosis patients in Harare, Zimbabwe

Setting

A resource-limited urban setting in Zimbabwe with a high burden of tuberculosis (TB) and human immunodeficiency virus (HIV).

Objectives

To determine the feasibility and yield of diabetes mellitus (DM) screening among TB patients in primary health care facilities.

Design

A descriptive study.

Results

Of the 1617 TB patients registered at 10 pilot facilities, close to two thirds (60%) were male and 798 (49%) were bacteriologically confirmed. The median age was 37 years; two thirds (67%) were co-infected with HIV. A total of 1305 (89%) were screened for DM, and 111 (8.5%, 95% CI 7.0-10.2) were newly diagnosed with DM. Low TB notifying sites were more likely than high TB notifying sites to screen patients using random blood glucose (RBG) (83% vs. 79%; P < 0.04). Screening increased gradually per quarter over the study period. There were, however, notable losses along the screening cascade, the reasons for which will need to be explored in future studies.

Conclusion

The study findings indicate the feasibility of DM screening among TB patients, with considerable yield of persons newly diagnosed with DM. Scaling up of this intervention will need to address the observed losses along the screening cascade.

Microwave Imaging Sensor Using Low Profile Modified Stacked Type Planar Inverted F Antenna

Microwave imaging is the technique to identify hidden objects from structures using electromagnetic waves that can be applied in medical diagnosis. The change of dielectric property can be detected using microwave antenna sensor, which can lead to localization of abnormality in the human body. This paper presents a stacked type modified Planar Inverted F Antenna (PIFA) as microwave imaging sensor. Design and performance analysis of the sensor antenna along with computational and experimental analysis to identify concealed object has been investigated in this study. The dimension of the modified PIFA radiating patch is 40 × 20 × 10 mm³. The reflector walls used, are 45 mm in length and 0.2-mm-thick inexpensive copper sheet is considered for the simulation and fabrication which addresses the problems of high expenses in conventional patch antenna. The proposed antenna sensor operates at 1.55–1.68 GHz where the maximum realized gain is 4.5 dB with consistent unidirectional radiation characteristics. The proposed sensor antenna is used to identify tumor in a computational human tissue phantom based on reflection and transmission coefficient. Finally, an experiment has been performed to verify the antenna’s potentiality of detecting abnormality in realistic breast phantom.

Unidirectional barbed suture for vaginal cuff closure without backward stitch in total laparoscopic hysterectomy

AIM

To evaluate the safety and efficacy of unidirectional barbed suture technique for vaginal cuff closure in total laparoscopic hysterectomy (TLH).

METHODS

In a retrospective chart review, data were analyzed from 165 patients who underwent a TLH with an unidirectional barbed suture technique for vaginal cuff closure from January 2012 to June 2016 at tertiary-care university-based teaching hospital and academic affiliated hospital. Vaginal cuff was closed by single layer 3/0 V-Loc unidirectional 9″, 180 day Absorbable Wound Closure Device (Covidien Healthcare, Mansfield, MA) and the suture was not stitched backward to secure distal end.

RESULTS

A total of 165 patients were included and the median age was 50 years (range, 35-84 years). The median completion time for hysterectomy time was 100 min (range, 40-240 min) and the median vaginal cuff closure time was 7 min (range, 4-15 min). The median estimated blood loss was 87.8 mL (range 30-250 mL) and the median uterine weight was 200 g (range, 40-900 g). Intraoperative complication included bladder perforation (1.2%) and postoperative complications were vaginal cuff dehiscence (1.8%), cuff cellulitis (0.6%), vesicovaginal fistula (0.6%) and unexplained fever (0.6%).

CONCLUSION

According to the results of current study, the use of unidirectional barbed suture without backward stitching appears to be safe for the vaginal cuff closure in TLH.

Temperature Rise in Kirschner Wires Inserted Using Two Drilling Methods: Forward and Oscillation

BACKGROUND

Kirschner wires (K-wires) are commonly used in orthopedic surgery. However, the loosening of the pins can lead to delayed or improper healing or infection. Wire loosening can occur by thermal necrosis that occurs due to heat produced during wire insertion. Although the parameters that affect temperature rise in cortical bone during wire insertion and drilling have been studied, the effect of drilling mode (oscillation versus forward) is unknown. The purpose of this study was to compare the temperature changes occurring in cortical bone during wire insertions by oscillating and forward drills. Our hypothesis is that oscillation drilling would produce less heat compared with forward drilling in K-wire insertion with 2 commonly used wire diameters.

METHODS

We drilled K-wires in a pig metacarpal model and measured the temperature rise between forward and oscillation drilling modes using diamond-tipped 0.062- and 0.045-inch-diameter K-wires. There were 20 holes drilled for each group (n = 20).

RESULTS

The average temperature rise using the 0.062-inch K-wire under forward and oscillation insertion was 14.0 ± 5.5°C and 8.8 ± 2.6°C, respectively. For the 0.045-inch K-wire, under forward and oscillation insertion, the average temperature rise was 11.4 ± 2.6°C and 7.1 ± 1.9°C, respectively. The effects of the drilling mode and wire diameter on temperature rise were significant ( P < .05).

CONCLUSIONS

In conclusion, the oscillation of K-wires during insertion causes a lower temperature rise when compared with forward drilling.

Intimate Partner Violence and Psychological Distress Among Young Couples: The Role of the Pattern of Violence

The objective of this study was to assess whether the psychological distress of young men and women involved in intimate partner violence (IPV) is predicted by their reported role in the pattern of violence. Dyadic structural equation modeling (SEM) analyses were performed on a sample of 205 young couples, controlling for income, cohabitation, children, and the length of the relationship. Findings revealed that the most common reported pattern of IPV was mutual in nature. Reported bidirectional violence within the couple was related to distress for both sexes. The couple's income and the length of their relationship were negatively associated with psychological distress, namely for young women. Findings point to the importance of considering therapy in a couple-context.

Artificial Slanted Nanocilia Array as a Mechanotransducer for Controlling Cell Polarity

We present a method to induce cell directional behavior using slanted nanocilia arrays. NIH-3T3 fibroblasts demonstrated bidirectional polarization in a rectangular arrangement on vertical nanocilia arrays and exhibited a transition from a bidirectional to a unidirectional polarization pattern when the angle of the nanocilia was decreased from 90° to 30°. The slanted nanocilia guided and facilitated spreading by allowing the cells to contact the sidewalls of the nanocilia, and the directional migration of the cells opposed the direction of the slant due to the anisotropic bending stiffness of the slanted nanocilia. Although the cells recognized the underlying anisotropic geometry when the nanocilia were coated with fibronectin, collagen type I, and Matrigel, the cells lost their directionality when the nanocilia were coated with poly-d-lysine and poly-l-lysine. Furthermore, although the cells recognized geometrical anisotropy on fibronectin coatings, pharmacological perturbation of PI3K-Rac signaling hindered the directional elongation of the cells on both the slanted and vertical nanocilia. Furthermore, myosin light chain II was required for the cells to obtain polarized morphologies. These results indicated that the slanted nanocilia array provided anisotropic contact guidance cues to the interacting cells. The polarization of cells was controlled through two steps: the recognition of underlying geometrical anisotropy and the subsequent directional spreading according to the guidance cues.

Resonance-Based Reflector and Its Application in Unidirectional Antenna with Low-Profile and Broadband Characteristics for Wireless Applications

In this research, the novel concept of a resonance-based reflector (RBR) was proposed, and a ring-shaped RBR was utilized to design a unidirectional antenna with low-profile and broadband characteristics. Research found the ring operates as two half-wavelength (λ/2) resonators. Then, the resonance effect transforms the reflection phase of the ring RBR, and achieves a reflection phase of 0° < ϕ < 180° in a wide frequency range above the resonance. Then, the in-phase reflection characteristic (−90° < ϕ < 90°) can be obtained in the wide frequency band by placing an antenna above the RBR with a distance smaller than λ/4. Two unidirectional antennas, named Case 1 and Case 2, were designed with the ring-shaped RBRs and bowtie antennas (RBR-BAs). The impedance bandwidths of Case 1 and the Case 2 are 2.04–5.12 GHz (86.3%) and 1.97–5.01 GHz (87.1%), respectively. The front-to-back ratio (FBR, an important parameter to measure the unidirectional radiation) of Case 1 ranges from 5–9.9 dB for frequencies 2.04–2.42 GHz, and the FBR of Case 2 ranges from 5–16 dB for frequencies 2.16–3.15 GHz. The proposed concept of RBR is desirable in wideband unidirectional antenna design, and the designing antennas can be used at the front end of wireless systems—such as indoors communication, remote sensing, and wireless sensor systems—for signal receiving or transmitting.

Precursor and oxygen dependence of the unidirectional, seeded growth of CdSe nanorods

It was recently shown that, by controlling the O(2) concentration, the seeded-growth of CdSe nanocrystals (NC) can be manipulated to proceed either unidirectionally (from the (0001) facet) or three-dimensionally. In this contribution, we investigate two new Se precursors (i.e. SeO(2) and NaHSe) and compare them with Se obtained from etching of smaller NC seeds. Under anaerobic conditions, both precursors led to successful 3-dimensional (3D) NC growth. At high O(2) concentrations, the seeded growth of rods was enhanced by the NaHSe precursor, while impeded by the use of SeO(2). Mechanistic studies showed that the reduction of SeO(2) to Se(2-) produces an excessive amount of O(2). This leads to rod fragmentation due to etching as well as the production of deep traps that quench their luminescence. These new precursors, along with a heightened understanding of oxygen's role, expand the synthetic repertoire of the redox-assisted, seeded-growth of CdSe and better position this low temperature (125 °C) methodology towards realizing advanced NC heterostructures.

Focal electrically administered seizure therapy: a novel form of ECT illustrates the roles of current directionality, polarity, and electrode configuration in seizure induction

Electroconvulsive therapy (ECT) is a mainstay in the treatment of severe, medication-resistant depression. The antidepressant efficacy and cognitive side effects of ECT are influenced by the position of the electrodes on the head and by the degree to which the electrical stimulus exceeds the threshold for seizure induction. However, surprisingly little is known about the effects of other key electrical parameters such as current directionality, polarity, and electrode configuration. Understanding these relationships may inform the optimization of therapeutic interventions to improve their risk/benefit ratio. To elucidate these relationships, we evaluated a novel form of ECT (focal electrically administered seizure therapy, FEAST) that combines unidirectional stimulation, control of polarity, and an asymmetrical electrode configuration, and contrasted it with conventional ECT in a nonhuman primate model. Rhesus monkeys had their seizure thresholds determined on separate days with ECT conditions that crossed the factors of current directionality (unidirectional or bidirectional), electrode configuration (standard bilateral or FEAST (small anterior and large posterior electrode)), and polarity (assignment of anode and cathode in unidirectional stimulation). Ictal expression and post-ictal suppression were quantified through scalp EEG. Findings were replicated and extended in a second experiment with the same subjects. Seizures were induced in each of the 75 trials, including 42 FEAST procedures. Seizure thresholds were lower with unidirectional than with bidirectional stimulation (p<0.0001), and lower in FEAST than in bilateral ECS (p=0.0294). Ictal power was greatest in posterior-anode unidirectional FEAST, and post-ictal suppression was strongest in anterior-anode FEAST (p=0.0008 and p=0.0024, respectively). EEG power was higher in the stimulated hemisphere in posterior-anode FEAST (p=0.0246), consistent with the anode being the site of strongest activation. These findings suggest that current directionality, polarity, and electrode configuration influence the efficiency of seizure induction with ECT. Unidirectional stimulation and novel electrode configurations such as FEAST are two approaches to lowering seizure threshold. Furthermore, the impact of FEAST on ictal and post-ictal expression appeared to be polarity dependent. Future studies may examine whether these differences in seizure threshold and expression have clinical significance for patients receiving ECT.