Interface engineering in ZnO/CdO hybrid nanocomposites to enhanced resistive switching memory for neuromorphic computing

Resistive random-access memory (RRAMs) has attracted significant interest for their potential applications in embedded storage and neuromorphic computing. Materials based on metal chalcogenides have emerged as promising candidates for the fulfilment of these requirements. Due to its ability to manipulate electronic states and control trap states through controlled compositional dynamics, metal chalcogenide RRAM has excellent non-volatile resistive memory properties. In the present we have synthesized ZnO-CdO hybrid nanocomposite by using hydrothermal method as an active layer. The Ag/C15ZO/Pt hybrid nanocomposite structure memristors showed electrical properties similar to biological synapses. The device exhibited remarkably stable resistive switching properties that have a low SET/RESET (0.41/-0.2) voltage, a high RON/OFF ratio of approximately 105, a high retention stability, excellent endurance reliability up to 104 cycles and multilevel device storage performance by controlling the compliance current. Furthermore, they exhibited an impressive performance in terms of emulating biological synaptic functions, which include long-term potentiation (LTP), long-term depression (LTD), and paired-pulse facilitation (PPF), via the continuous modulation of conductance. The hybrid nanocomposite memristors notably achieved an impressive recognition accuracy of up to 92.6 % for handwritten digit recognition under artificial neural network (ANN). This study shows that hybrid-nanocomposite memristor performance could lead to efficient future neuromorphic architectures.

Broadening spectral responses and achieving environmental stability in SnS2/Ag-NPs/HfO2 flexible phototransistors

Layered two-dimensional (2D) materials have gained popularity thanks to their atomically thin physique and strong coupling with light. Here, we investigated a wide band gap (≥ 2 eV) 2D material, i.e., tin disulfide (SnS2), and decorated it with silver nanoparticles, Ag-NPs, for broadband photodetection. Our results show that the SnS2/Ag-NPs devices exhibit broadband photodetection ranging from the ultraviolet to near-infrared (250-1050 nm) spectrum with decreased rise/decay times from 8/20 s to 7/16 s under 250 nm wavelength light compared to the bare SnS2 device. This is attributed to the localized surface plasmon resonance effect and the wide band gap of SnS2 crystal. Furthermore, the HfO2-passivated SnS2/Ag-NPs devices exhibited high photodetection performance in terms of photoresponsivity (∼12 500 A W-1), and external quantum efficiency (∼6 × 106%), which are significantly higher compared to those of bare SnS2. Importantly, after HfO2 passivation, the SnS2/Ag-NPs photodetector maintained the stable performance for several weeks with merely ∼5.7% reduction in photoresponsivity. Lastly, we fabricated a flexible SnS2/Ag-NPs photodetector, which shows excellent and stable performance under various bending curvatures (0, 20, and 10 mm), as it retains ∼80% of its photoresponsivity up to 500 bending cycles. Thus, our study provides a simple route to realize broadband and stable photoactivity in flexible 2D material-based devices.

Effect of growth temperature on self-rectifying BaTiO3/ZnO heterojunction for high-density crossbar arrays and neuromorphic computing

In the quest for high-density integration and massive scalability, ferroelectric-based devices provide an achievable approach for nonvolatile crossbar array (CBA) architecture and neuromorphic computing. In this report, ferroelectric-semiconductor (Pt/BaTiO3/ZnO/Au) heterojunction-based devices are demonstrated to exhibit nonvolatile and synaptic characteristics. In this study, the ferroelectric (BaTiO3) layer was modulated at various growth temperatures of 350 °C, 450 °C, 550 °C and 650 °C. Growing temperature in the ferroelectric layer has a significant impact on resistive switching. The ferroelectricity of the BaTiO3 thin film enhanced by increasing temperature causes a substantial shift in the interface state density at heterojunction interface, which is crucial for self-rectification. Furthermore, this self-rectifying property advances to reduce the crosstalk problem without any selector device. Enhanced resistive switching and neuromorphic applications have been demonstrated using BaTiO3 heterostructure devices at 550 °C. The dynamic ferroelectric polarization switching in this heterojunction demonstrated linear conductance change in artificial synapses with 91 % recognition accuracy. Ferroelectric polarization reversal with a depletion region at the heterojunction interface is the responsible mechanism for the switching in these devices. Thus, these findings pave the way for designing low power high-density crossbar arrays and neuromorphic application based on ferroelectric-semiconductor heterostructures.

A self-tuning PID controller based on analog-digital hybrid computing with a double-gate SnS2 memtransistor

Most commercial drones utilize a traditional proportional-integral-derivative (PID) controller because of its design simplicity. However, the traditional PID controller has certain limitations in terms of optimality and robustness; it is difficult to actively adjust the PID gains under some disturbances. In this study, we demonstrated an analog-digital hybrid computing platform based on double-gate SnS2 memtransistors to implement a self-tuning/energy-efficient PID controller in drones. The customized analog circuit with memtransistors executes the PID control algorithm with low power consumption; we experimentally verified that the energy consumption of the proposed hybrid computing-based PID controller is only 63% of that of the traditional PID controller. In addition, the precise tunability of analog conductance states in the memtransistor proved to be capable of reconfiguring the performance of the PID controller, where the developed self-tuning algorithm can automatically find the optimal PID control performance.

Optically Reconfigurable Complementary Logic Gates Enabled by Bipolar Photoresponse in Gallium Selenide Memtransistor

To avoid the complexity of the circuit for in-memory computing, simultaneous execution of multiple logic gates (OR, AND, NOR, and NAND) and memory behavior are demonstrated in a single device of oxygen plasma-treated gallium selenide (GaSe) memtransistor. Resistive switching behavior with R_ON /R_OFF ratio in the range of 10⁴ to 10⁶ is obtained depending on the channel length (150 to 1600 nm). Oxygen plasma treatment on GaSe film created shallow and deep-level defect states, which exhibit carriers trapping/de-trapping, that lead to negative and positive photoconductance at positive and negative gate voltages, respectively. This distinguishing feature of gate-dependent transition of negative to positive photoconductance encourages the execution of four logic gates in the single memory device, which is elusive in conventional memtransistor. Additionally, it is feasible to reversibly switch between two logic gates by just adjusting the gate voltages, e.g., NAND/NOR and AND/NAND. All logic gates presented high stability. Additionally, memtransistor array (1×8) is fabricated and programmed into binary bits representing ASCII (American Standard Code for Information Interchange) code for the uppercase letter "N". This facile device configuration can provide the functionality of both logic and memory devices for emerging neuromorphic computing.

Flexible Organic-Inorganic Halide Perovskite-Based Diffusive Memristor for Artificial Nociceptors

With the current evolution in the artificial intelligence technology, more biomimetic functions are essential to execute increasingly complicated tasks and respond to challenging work environments. Therefore, an artificial nociceptor plays a significant role in the advancement of humanoid robots. Organic-inorganic halide perovskites (OHPs) have the potential to mimic the biological neurons due to their inherent ion migration. Herein, a versatile and reliable diffusive memristor built on an OHP is reported as an artificial nociceptor. This OHP diffusive memristor showed threshold switching properties with excellent uniformity, forming-free behavior, a high I_ON/I_OFF ratio (10⁴), and bending endurance over >10² cycles. To emulate the biological nociceptor functionalities, four significant characteristics of the artificial nociceptor, such as threshold, no adaptation, relaxation, and sensitization, are demonstrated. Further, the feasibility of OHP nociceptors in artificial intelligence is being investigated by fabricating a thermoreceptor system. These findings suggest a prospective application of an OHP-based diffusive memristor in the future neuromorphic intelligence platform.

364 Systematic Review of Simulation-Based Training Tools in Plastic Surgery

Aim

The recent shift from traditional surgical teaching to the incorporation of simulation training in plastic surgery has resulted in the development of a variety of simulation models and tools. We aim to identify all currently available simulators and tools for plastic surgery, assess their validity and establish their effectiveness.

Method

MEDLINE and Embase were searched for articles which validate simulation models in plastic surgery. Each study was screened in accordance with the Messick validity framework, and a rating was given for each section. In order to determine the effectiveness of each study, the McGaghie model of translational outcomes was used.

Results

On screening 2104 articles, 71 were identified to discuss validity and effectiveness. Only one study was found to achieve a high score in all validity parameters and no studies achieved an effectiveness level >2.

Conclusions

With the increasing amount of simulation training tools, there must be more validity studies conducted using updated validity frameworks. In addition, there should be an increased emphasis of the relationship between these simulators and patient outcomes/surgical technique in the operating theatre in order to determine translational outcomes. More training tools evaluating both technical and nontechnical surgical skills are recommended.

The non-volatile electrostatic doping effect in MoTe2 field-effect transistors controlled by hexagonal boron nitride and a metal gate

The electrical and optical properties of transition metal dichalcogenides (TMDs) can be effectively modulated by tuning their Fermi levels. To develop a carrier-selectable optoelectronic device, we investigated intrinsically p-type MoTe₂, which can be changed to n-type by charging a hexagonal boron nitride (h-BN) substrate through the application of a writing voltage using a metal gate under deep ultraviolet light. The n-type part of MoTe₂ can be obtained locally using the metal gate pattern, whereas the other parts remain p-type. Furthermore, we can control the transition rate to n-type by applying a different writing voltage (i.e., − 2 to − 10 V), where the n-type characteristics become saturated beyond a certain writing voltage. Thus, MoTe₂ was electrostatically doped by a charged h-BN substrate, and it was found that a thicker h-BN substrate was more efficiently photocharged than a thinner one. We also fabricated a p–n diode using a 0.8 nm-thick MoTe₂ flake on a 167 nm-thick h-BN substrate, which showed a high rectification ratio of ~ 10⁻⁴. Our observations pave the way for expanding the application of TMD-based FETs to diode rectification devices, along with optoelectronic applications.

Analog-digital hybrid computing with SnS2 memtransistor for low-powered sensor fusion

Algorithms for intelligent drone flights based on sensor fusion are usually implemented using conventional digital computing platforms. However, alternative energy-efficient computing platforms are required for robust flight control in a variety of environments to reduce the burden on both the battery and computing power. In this study, we demonstrated an analog–digital hybrid computing platform based on SnS₂ memtransistors for low-power sensor fusion in drones. The analog Kalman filter circuit with memtransistors facilitates noise removal to accurately estimate the rotation of the drone by combining sensing data from the gyroscope and accelerometer. We experimentally verified that the power consumption of our hybrid computing-based Kalman filter is only 1/4^th of that of the traditional software-based Kalman filter.

Analog–digital hybrid computing based on SnS2 memtransistors is demonstrated for lowpower sensor fusion in drones, where a drone with hybrid computing performs sensor fusion with higher energy efficiency than that with only a digital processor.

Controlling the Wettability of ZnO Thin Films by Spray Pyrolysis for Photocatalytic Applications

Herein, we synthesized the zinc oxide (ZnO) thin films (TFs) deposited on glass substrates via spray pyrolysis (SP) to prepare self-cleaning glass. Various process parameters were used to optimize photocatalytic performance. Substrates were coated at room temperature (RT) and 250 °C with a 1 mL or 2 mL ZnO solution while maintaining a distance from the spray gun to the substrate of 20 cm or 30 cm. Several characterization techniques, i.e., XRD, SEM, AFM, and UV–Vis were used to determine the structural, morphological, and optical characteristics of the prepared samples. The wettability of the samples was evaluated using contact angle measurements. As ZnO is hydrophilic in nature, the RT deposited samples showed a hydrophilic character, whereas the ZnO TFs deposited at 250 °C demonstrated a hydrophobic character. The XRD results showed a higher degree of crystallinity for samples deposited on heated substrates. Because of this higher crystallinity, the surface energy decreased, and the contact angle increased. Moreover, by using 2 mL solution, better surface coverage and roughness were obtained for the ZnO TFs. However, by exploiting the distance of the spray to the samples size distribution and surface coverage can be controlled, the samples deposited at 30 mL showed a uniform particle size distribution from 30–40 nm. In addition, the photoactivity of the samples was tested by the degradation of rhodamine B dye. Substrates prepared with a 2 mL solution sprayed at 20 cm showed higher dye degradation than other samples, which can play a vital role in self-cleaning. Hence, by changing the said parameters, the ZnO thin film properties on glass substrates were optimized for self-cleaning diversity.

Significant production of vanillin and in vitro amplification of ech gene in local bacterial isolates

Vanillin is the major component which is responsible for flavor and aroma of vanilla extract and is produced by 3 ways: natural extraction from vanilla plant, chemical synthesis and from microbial transformation. Current research was aimed to study bacterial production of vanillin from native natural sources including sewage and soil from industrial areas. The main objective was vanillin bio-production by isolating bacteria from these native sources. Also to adapt methodologies to improve vanillin production by optimized fermentation media and growth conditions. 47 soil and 13 sewage samples were collected from different industrial regions of Lahore, Gujranwala, Faisalabad and Kasur. 67.7% bacterial isolates produced vanillin and 32.3% were non-producers. From these 279 producers, 4 bacterial isolates selected as significant producers were; A3, A4, A7 and A10. These isolates were identified by ribotyping as A3 Pseudomonas fluorescence (KF408302), A4 Enterococcus faecium (KT356807), A7 Alcaligenes faecalis (MW422815) and A10 Bacillus subtilis (KT962919). Vanillin producers were further tested for improved production of vanillin and were grown in different fermentation media under optimized growth conditions for enhanced production of vanillin. The fermentation media (FM) were; clove oil based, rice bran waste (residues oil) based, wheat bran based and modified isoeugenol based. In FM5, FM21, FM22, FM23, FM24, FM30, FM31, FM32, FM34, FM35, FM36, and FM37, the selected 4 bacterial strains produced significant amounts of vanillin. A10 B. subtilis produced maximum amount of vanillin. This strain produced 17.3 g/L vanillin in FM36. Cost of this fermentation medium 36 was 131.5 rupees/L. This fermentation medium was modified isoeugenol based medium with 1% of isoeugenol and 2.5 g/L soybean meal. ech gene was amplified in A3 P. fluorescence using ech specific primers. As vanillin use as flavor has increased tremendously, the bioproduction of vanillin must be focused.

555 Should All Acutely Presenting Gallstone Disease Be Managed Surgically?

Aim

This audit aims to assess if gallstone complications can be prevented by performing an emergency cholecystectomy in acutely presenting gallstone disease. Factors taken into consideration include number of presentations to hospital before surgery, secondary admissions of pancreatitis or cholangitis, subsequent requirements of ERCP as well as complication rates of elective and emergency surgery.

Method

Retrospective audit looking at 387 cholecystectomies carried out, within a year, at Walsall Manor Hospital.

Results

Approximately 20% of patients had an emergency cholecystectomy. A total of 192 patients had at least one admission, with 17% having a minimum second. Seven patients went on to develop gallstone pancreatitis subsequently, as well as eight requiring at least a minimum of one ERCP. The complication rate in elective surgery was higher at 4.1% compared to 2.7% in emergency cases. Long waiting times for surgery put patients at greater risk of complications. 96% (26/27) of elective cholecystectomy patients, who suffered an attack of pancreatitis, had to wait more than four weeks. Furthermore, 39% (47/119) of those who had a minimum of one admission had to wait more than 20 weeks. On the other hand, three-quarters of patients who were operated in emergency went home within 48 hours, with the figures being not too dissimilar from elective cases with a history of admission (76%).

Conclusions

Performing emergency cholecystectomies in the same admission or on a dedicated hot list would not only decrease the risk, but also the potential risk of developing gallstone complications.

Modulating the production of xylanase by Bacillus pumilus BS131 through optimization using waste fiber sludge

In recent days, cheapest alternative carbon source for fermentation purpose is desirable to minimize production cost. Xylanases have become attractive enzymes as their potential in bio-bleaching of pulp and paper industry. The objective of the present study was to identify the potential ability on the xylanase production by locally isolated Bacillus pumilus BS131 by using waste fiber sludge and wheat bran media under submerged fermentation. Culture growth conditions were optimized to obtain significant amount of xylanase. Maximum xylanase production was recorded after 72 hours of incubation at 30 °C and 7 pH with 4.0% substrate concentration. In the nutshell, the production of xylanase using inexpensive waste fiber sludge and wheat-bran as an alternative in place of expensive xylan substrate was more cost effective and environment friendly.

Stable and Multilevel Data Storage Resistive Switching of Organic Bulk Heterojunction

Organic nonvolatile memory devices have a vital role for the next generation of electrical memory units, due to their large scalability and low-cost fabrication techniques. Here, we show bipolar resistive switching based on an Ag/ZnO/P3HT-PCBM/ITO device in which P3HT-PCBM acts as an organic heterojunction with inorganic ZnO protective layer. The prepared memory device has consistent DC endurance (500 cycles), retention properties (104 s), high ON/OFF ratio (105), and environmental stability. The observation of bipolar resistive switching is attributed to creation and rupture of the Ag filament. In addition, our conductive bridge random access memory (CBRAM) device has adequate regulation of the current compliance leads to multilevel resistive switching of a high data density storage.

Neuro-Transistor Based on UV-Treated Charge Trapping in MoTe2 for Artificial Synaptic Features

The diversity of brain functions depend on the release of neurotransmitters in chemical synapses. The back gated three terminal field effect transistors (FETs) are auspicious candidates for the emulation of biological functions to recognize the proficient neuromorphic computing systems. In order to encourage the hysteresis loops, we treated the bottom side of MoTe₂ flake with deep ultraviolet light in ambient conditions. Here, we modulate the short-term and long-term memory effects due to the trapping and de-trapping of electron events in few layers of a MoTe₂ transistor. However, MoTe₂ FETs are investigated to reveal the time constants of electron trapping/de-trapping while applying the gate-voltage pulses. Our devices exploit the hysteresis effect in the transfer curves of MoTe₂ FETs to explore the excitatory/inhibitory post-synaptic currents (EPSC/IPSC), long-term potentiation (LTP), long-term depression (LTD), spike timing/amplitude-dependent plasticity (STDP/SADP), and paired pulse facilitation (PPF). Further, the time constants for potentiation and depression is found to be 0.6 and 0.9 s, respectively which seems plausible for biological synapses. In addition, the change of synaptic weight in MoTe₂ conductance is found to be 41% at negative gate pulse and 38% for positive gate pulse, respectively. Our findings can provide an essential role in the advancement of smart neuromorphic electronics.

High performance complementary WS2 devices with hybrid Gr/Ni contacts

Two-dimensional (2D) transition metal dichalcogenides have attracted vibrant interest for future solid-state device applications due to their unique properties. However, it is challenging to realize 2D material based high performance complementary devices due to the stubborn Fermi level pinning effect and the lack of facile doping techniques. In this paper, we reported a hybrid Gr/Ni contact to WS2, which can switch carrier types from n-type to p-type in WS2. The unorthodox polarity transition is attributed to the natural p-doping of graphene with Ni adsorption and the alleviation of Fermi level pinning in WS2. Furthermore, we realized asymmetric Ni and Gr/Ni hybrid contacts to a multilayer WS2 device, and we observed synergistic p-n diode characteristics with excellent current rectification exceeding 104, and a near unity ideality factor of 1.1 (1.6) at a temperature of 4.5 K (300 K). Lastly, our WS2 p-n device exhibits high performance photovoltaic ability with a maximum photoresponsivity of 4 × 104 A W-1 at 532 nm wavelength, that is 108 times higher than that of graphene and 50 times better than that of the monolayer MoS2 photodetector. This doping-free carrier type modulation technique will pave the way to realize high performance complementary electronics and optoelectronic devices based on 2D materials.

Chemical Nature of Electrode and the Switching Response of RF-Sputtered NbOx Films

In this study, the dominant role of the top electrode is presented for Nb₂O₅-based devices to demonstrate either the resistive switching or threshold characteristics. These Nb₂O₅-based devices may exhibit different characteristics depending on the selection of electrode. The use of the inert electrode (Au) initiates resistive switching characteristics in the Au/Nb₂O₅/Pt device. Alternatively, threshold characteristics are induced by using reactive electrodes (W and Nb). The X-ray photoelectron spectroscopy analysis confirms the presence of oxide layers of WO_y and NbO_x at interfaces for W and Nb as top electrodes. However, no interface layer between the top electrode and active layer is detected in X-ray photoelectron spectroscopy for Au as the top electrode. Moreover, the dominant phase is Nb₂O₅ for Au and NbO₂ for W and Nb. The threshold characteristics are attributed to the reduction of Nb₂O₅ phase to NbO₂ due to the interfacial oxide layer formation between the reactive top electrode and Nb₂O₅. Additionally, reliability tests for both resistive switching and threshold characteristics are also performed to confirm switching stabilities.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Modulation of Magnetoresistance Polarity in BLG/SL-MoSe2 Heterostacks

Two-dimensional (2D) layered materials have an atomically thin and flat nature which makes it an ultimate candidate for spintronic devices. The spin-valve junctions (SVJs), composed of 2D materials, have been recognized as unique features of spin transport polarization. However, the magnetotransport properties of SVJs are highly influenced by the type of intervening layer (spacer) inserted between the ferromagnetic materials (FMs). In this situation, the spin filtering effect at the interfaces plays a critical role in the observation of the magnetoresistance (MR) of such magnetic structures, which can be improved by using promising hybrid structure. Here, we report MR of bilayer graphene (BLG), single-layer MoSe₂ (SL-MoSe₂), and BLG/SL-MoSe₂ heterostack SVJs. However, before annealing, BLG and SL-MoSe₂ SVJs demonstrate positive MR, but after annealing, BLG reverses its polarity while the SL-MoSe₂ maintains its polarity and demonstrated stable positive spin polarizations at both interfaces due to meager doping effect of ferromagnetic (FM) contacts. Further, Co/BLG/SL-MoSe₂/NiFe determines positive MR, i.e., ~ 1.71% and ~ 1.86% at T = 4 K before and after annealing, respectively. On the contrary, NiFe/BLG/SL-MoSe₂/Co SVJs showed positive MR before annealing and subsequently reversed its MR sign after annealing due to the proximity-induced effect of metals doping with graphene. The obtained results can be useful to comprehend the origin of polarity and the selection of non-magnetic material (spacer) for magnetotransport properties. Thus, this study established a new paragon for novel spintronic applications.

Synthesis of Dy-Y co-substituted manganese‑zinc spinel nanoferrites induced anti-bacterial and anti-cancer activities: Comparison between sonochemical and sol-gel auto-combustion methods

This study described the beneficial properties of ultrasonic irradiation approach to synthesize the spinel-type Dy-Y co-substituted Mn-Zn nanospinel ferrites (NSFs). We have used two different approaches like citrate sol-gel combustion and ultrasonic irradiation routes to produced series of Mn_0.5Zn_0.5Fe_2-2x(Dy_xY_x)O₄ (0.0 ≤ x ≤ 0.05) NSFs (DyY-MnZn NSFs). The structure and morphology of NSFs X-was examined by using XRD, EDX, SEM and TEM methods. We have found that spinel ferrites and hematite phase in DyY-MnZn NSFs produced by citrate sol-gel, while DyY-MnZn NSFs created by ultrasonic irradiation contain a pure phase of spinel ferrite. TEM analysis revealed the spherical nanoparticles with fairly uniform size. We have also analyzed the biological applications of DyY-MnZn NSFs prepared by both methods (ultrasonication and sol-gel) by examining their anti-cancer and anti-bacterial (Escherichia coli and Staphylococcus aureu) activities. We have found that both methods produced inhibitory actions on colon cancer cells (HCT-116) and bacterial cells, whereas, no inhibitory action was observed when examined on normal and non-cancerous cells (HEK-293).

Synthesis of Ni0.5Co0.5-xCdxFe1.78Nd0.02O4 (x ≤ 0.25) nanofibers by using electrospinning technique induce anti-cancer and anti-bacterial activities

Here we report the electrospinning synthesis of Cd-substituted Ni-Co ferrite Ni_0.5Co_0.5-xCd_xFe_1.78Nd_0.02O₄ (x ≤ 0.25) nanofiber (NFs) with a very low concentration of Nd as a dopant. The structure and surface morphology of the Ni_0.5Co_0.5-xCd_xFe_1.78Nd_0.02O₄ (x ≤ 0.25) NFs were analyzed by X-ray powder pattern (XRD), transmission and scanning electron microscopes (TEM) along with Energy-dispersive X-ray (EDX). We have examined the biological applications of the Ni_0.5Co_0.5-xCd_xFe_1.78Nd_0.02O₄ (x ≤ 0.25) NFs on both cancerous cells and bacterial cells. We have found that Ni_0.5Co_0.5-xCd_xFe_1.78Nd_0.02O₄ (x ≤ 0.25) NFs produced inhibitory action on the human colorectal carcinoma cells (HEK-293) and also showed inhibitory action on the bacterial strains (S. aureus and E. coli) respectively. Finally, this is the first report on the synthesis of Cd- substituted Co-Ni ferrite nanofibers using electrospinning technique exhibiting anti-cancer and anti-bacterial activities.Communicated by Ramaswamy H. Sarma.

METASTATIC HÜRTHLE CELL CARCINOMA PRESENTING WITH LOW FREE THYROXINE, SEVERE HYPERCALCEMIA AND SPURIOUS GROWTH HORMONE PRODUCTION

Objective

Hürthle cell tumors constitute about 5% of thyroid neoplasms. They have malignant potential, behaving very aggressively compared to other differentiated thyroid cancers. The objective of this case report is to describe a case of a Hürthle cell carcinoma with a single large metastasis in the liver presenting almost 17 years after hemithyroidectomy. We highlight the difficulties in making a histologic diagnosis and the unpredictable nature of this cancer.

Methods

The patient history and biochemistry were detailed. Thyroid function tests analyzed on multiple platforms (single-photon emission computed tomography, dynamic magnetic resonance imaging, technetium-99m bone scan, and radioactive iodine) were used to aid biochemical and radiologic diagnosis.

Results

The patient's thyroid function test showed persistently low free thyroxine concentrations with normal thyroid stimulating hormone and free triiodothyronine, suggesting rapid deiodination in the context of a large liver lesion. Radiologic and morphologic appearances of the liver lesion led to an initial misdiagnosis of primary hepato-cellular carcinoma, revised to metastatic Hürthle cell carcinoma after positive immunochemistry. Nonparathyroid hormone-related intractable hypercalcemia of malignancy with an unusual pattern of elevated 1,25-dihydroxyvitamin D and raised fibroblast growth factor 23 concentrations culminated in his demise.

Conclusions

In Hürthle cell carcinomas treated with partial thyroidectomy, subsequent abnormal thyroid functions tests may herald a more sinister underlying diagnosis. The management of Hürthle cell carcinoma relies heavily on the initial histology results. Histologic diagnosis should be sought earlier in abnormal and suspicious distant masses. Malignant hypercalcemia poses a great challenge in delayed presentations and can prove resistant to conventional treatments.

Enhanced electrical and broad spectral (UV-Vis-NIR) photodetection in a Gr/ReSe2/Gr heterojunction

Excellent electrical and photoelectrical study of vertical integration by layered two-dimensional materials having gate tunable broad spectral (UV-Vis-NIR) light detection response.

Tuning of ionic mobility to improve the resistive switching behavior of Zn-doped CeO2

Correlation between the resistive switching characteristics of Au/Zn-doped CeO2/Au devices and ionic mobility of CeO2 altered by the dopant concentration were explored. It was found that the ionic mobility of CeO2 has a profound effect on the operating voltages of the devices. The magnitude of operating voltage was observed to decrease when the doping concentration of Zn was increased up to 14%. After further increasing the doping level to 24%, the device hardly exhibits any resistive switching. At a low doping concentration, only isolated Vo existed in the CeO2 lattice. At an intermediate doping concentration, the association between dopant and Vo formed (Zn, Vo)× defect clusters. Low number density of these defect clusters initially favored the formation of Vo filament and led to a reduction in operating voltage. As the size and number density of (Zn, Vo)× defect clusters increased at a higher doping concentration, the ionic conductivity was limited with the trapping of isolated Vo by these defect clusters, which resulted in the diminishing of resistive switching. This research work provides a strategy for tuning the mobility of Vo to modulate resistive switching characteristics for non-volatile memory applications.

Synthesis and biological characterization of Mn0.5Zn0.5EuxDyxFe1.8-2xO4 nanoparticles by sonochemical approach

Metallic nanoparticles (NPs) possess unique properties which makes them attractive candidates for various applications especially in field of experimental medicine and drug delivery. Many approaches were developed to synthesize divers and customized metallic NPs that can be useful in many areas such as, experimental medicine, drug design, drug delivery, electrical and electronic engineering, electrochemical sensors, and biochemical sensors. Among different metallic nanoparticles, manganese (Mn) NPs are the most prominent materials, in the present study, we have synthetized unique Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs by using ultrasonication method (x ≤ 0.1). The structure, and surface morphology of Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs was characterized by XRD, SEM, TEM and EDX methods. We have examined the biological effects of Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs on both normal (HEK-293) and cancerous (HCT-116) cells. We have found that the treatment of Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs post 48 h, showed significant decline in cancer cells population as revealed by MTT assay. The IC₅₀ value of Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs was ranged between (2.35 μg/mL to 2.33 μg/mL). To check the specificity of the actions, we found that the treatment of Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs did not produce any effects on the normal cells, which suggest that Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs selectively targeted the cancerous cells. The anti-bacterial properties of Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs were also evaluated by MIC and MBC assays. We suggest that Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs produced by sonochemical method possess potential anti-cancer and anti-bacterial capabilities.

Differential interference contrast microscopy for cells using hard x-ray holography

We propose a differential interference contrast method for cells using hard x-ray Gabor holography and knife-edge filtering in the spatial frequency domain, without relying on beam shearing. A phase object is holographically recorded and reconstructed by computer. Interference between the wavefronts of zeroth order weighted by e^jπ/2 in the positive frequency region produces a dark image. Similarly, interference between the wavefronts of the zeroth order weighted by e^j3π/2 in the negative frequency region produces a bright image. By adding these two intensity distributions, good quality phase-contrast images of 8-μm-diameter polystyrene beads and human HeLa cells were obtained.

Early vs delayed closure of loop defunctioning ileostomy in patients undergoing distal colorectal resections: an integrated systematic review and meta-analysis of published randomized controlled trials

AIMS

The objective of this study was to evaluate the surgical outcomes and feasibility of early loop defunctioning ileostomy closure, within 2 weeks of index surgery, in patients undergoing distal colorectal resection.

METHODS

A systematic review of the literature on published randomized controlled trials reporting the feasibility and outcomes on early vs delayed closure of loop defunctioning ileostomy in patients undergoing distal colorectal resection using the principles of meta-analysis on RevMan 5.4 statistical software was undertaken.

RESULTS

Four randomized, controlled trials on 446 patients evaluating the feasibility and outcomes on early vs delayed closure of loop defunctioning ileostomy in patients undergoing low colorectal resection were analysed. There were 176 patients in the early closure group and 270 patients in the delayed closure group. The risk of anastomotic leak [risk ratio 0.37 (CI: 0.10-1.42), P = 0.15], anastomotic stenosis [risk ratio 4.79 (CI: 0.23-98.47), P = 0.31] and postoperative complications [risk ratio 0.75 (CI: 0.48-1.16), P = 0.19] was similar in both groups. In addition, there was no significant difference between the groups with regard to the duration of operation [standardized mean difference -0.49 (CI: -01.09, -0.12), P = 0.12] and length of hospitalization [standardized mean difference -0.04 (CI: -0.25, -0.18), P = 0.75].

CONCLUSIONS

Early closure of loop defunctioning ileostomy in patients undergoing distal colorectal resection is feasible with comparable outcomes to delayed closure.

Combining 3D human in vitro methods for a 3Rs evaluation of novel titanium surfaces in orthopaedic applications

In this study, we report on a group of complementary human osteoblast in vitro test methods for the preclinical evaluation of 3D porous titanium surfaces. The surfaces were prepared by additive manufacturing (electron beam melting [EBM]) and plasma spraying, allowing the creation of complex lattice surface geometries. Physical properties of the surfaces were characterized by SEM and profilometry and 3D in vitro cell culture using human osteoblasts. Primary human osteoblast cells were found to elicit greater differences between titanium sample surfaces than an MG63 osteoblast-like cell line, particularly in terms of cell survival. Surface morphology was associated with higher osteoblast metabolic activity and mineralization on rougher titanium plasma spray coated surfaces than smoother surfaces. Differences in osteoblast survival and metabolic activity on titanium lattice structures were also found, despite analogous surface morphology at the cellular level. 3D confocal microscopy identified osteoblast organization within complex titanium surface geometries, adhesion, spreading, and alignment to the biomaterial strut geometries. Mineralized nodule formation throughout the lattice structures was also observed, and indicative of early markers of bone in-growth on such materials. Testing methods such as those presented are not traditionally considered by medical device manufacturers, but we suggest have value as an increasingly vital tool in efficiently translating pre-clinical studies, especially in balance with current regulatory practice, commercial demands, the 3Rs, and the relative merits of in vitro and in vivo studies. Biotechnol. Bioeng. 2016;113: 1586-1599. © 2015 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc.

Factors associated with failure to achieve a glycated haemoglobin target of <8.0% in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial

The aim of this study was to identify the clinical features of participants in the standard therapy arm of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) glycaemia trial who failed to reach the glycated haemoglobin (HbA1c) target. We analysed 4685 participants in the standard therapy arm, comparing participants who reached the HbA1c target of <8.0% with those whose HbA1c level was ≥8.0% 12 months after randomization. Baseline and 12-month clinical characteristics were compared. At 12 months after randomization, 3194 participants had HbA1c <8.0% and 1491 had HbA1c ≥8.0%. Black race [odds ratio (OR) 0.74, 95% confidence interval (CI) 0.61-0.89; p = 0.002], severe hypoglycaemia (OR 0.57, CI 0.37-0.89; p = 0.014) and insulin use (OR 0.51, CI 0.40-0.65; p < 0.001) were associated with failure to reach HbA1c goal at 12 months in the adjusted model. Even with free medications, free visits with clinicians and aggressive titration of medications, >30% of participants in the standard arm of the ACCORD trial had an HbA1c ≥8.0% at 1 year. Participants who were black, had severe hypoglycaemia and were on insulin were more likely to have an above-target HbA1c concentration after 12 months on the standard protocol.