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Non-fullerene based organic solar cells display a high initial power conversion efficiency but continue to suffer from poor thermal stability, especially in case of devices with thick active layers. Mixing of five structurally similar acceptors with similar electron affinities, and blending with a donor polymer is explored, yielding devices with a power conversion efficiency of up to 17.6%. The hexanary device performance is unaffected by thermal annealing of the bulk-heterojunction active layer for at least 23 days at 130 °C in the dark and an inert atmosphere. Moreover, hexanary blends offer a high degree of thermal stability for an active layer thickness of up to 390 nm, which is advantageous for high-throughput processing of organic solar cells. Here, a generic strategy based on multi-component acceptor mixtures is presented that permits to considerably improve the thermal stability of non-fullerene based devices and thus paves the way for large-area organic solar cells., (© 2023. The Author(s).)

Health outcomes in the state of Jammu and Kashmir have shown improvement in recent decades. However, nutritional achievements, particularly among children under the age of five, have not seen similar progress. Various factors influence the nutritional status of this age group, with the socio-cultural and biological attributes of mothers being considered significant determinants. While some studies have examined these attributes, there is a scarcity of research exploring the causal link between socio-culturally determined factors, such as maternal education, and child nutritional achievements, especially in Indian states located in North India. This paper aims to address this gap by analysing the prevalence of acute malnutrition (stunting) among children under five in Jammu and Kashmir in relation to educational inequality among mothers. The latest round of the National Family Health Survey (NFHS-5) is used to assess the levels of stunting (low height for age) among children, considering the literacy status of mothers and other control variables. Bivariate and multivariable methods are employed to study the association and identify risk factors. Additionally, the Oaxaca decomposition method is used to analyse the educational gap in factors associated with child stunting. The results indicate a higher prevalence of stunting among children of uneducated mothers (29%) compared to those of educated mothers (25%). The findings demonstrate a lower risk of stunting among children whose mothers are literate (OR 0.89). The Oaxaca decomposition analysis reveals a statistically significant difference in stunting between children based on their mother's education. These results highlight the wide disparities in acute malnutrition among children due to variations in maternal education. It is therefore crucial for policymakers to prioritize efforts to reduce educational disparities in order to alleviate the nutritional burden faced by children., (© 2023. The Author(s).)

Many severe epidemics and pandemics have hit human civilizations throughout history. The recent Sever Actuate Respiratory disease SARS-CoV-2 known as COVID-19 became a global disease and is still growing around the globe. It has severely affected the world's economy and ways of life. It necessitates predicting the spread in advance and considering various control policies to avoid the country's complete closure. In this paper, we propose deep learning-based stacked Bi-directional long short-term memory (Stacked Bi-LSTM) network that forecasts COVID-19 more accurately for the country of South Korea. The paper's main objectives are to present a lightweight, accurate, and optimized model to predict the spread considering restriction policies such as school closure, workspace closing, and the canceling of public events. Based on the fourteen parameters (including control policies), we predict and forecast the future value of the number of positive, dead, recovered, and quarantined cases. In this paper, we use the dataset of South Korea comprised of several control policies implemented for minimizing the spread of COVID-19. We compare the performance of the stacked Bi-LSTM with the traditional time-series models and LSTM model using the performance metrics mean absolute error (MAE), mean absolute percentage error (MAPE), and root mean square error (RMSE). Moreover, we study the impact of control policies on forecasting accuracy. We further study the impact of changing the Bi-LSTM default activation functions Tanh with ReLU on forecasting accuracy. The research provides insight to policymakers to optimize the pooling of resources more optimally on the correct date and time prior to the event and to control the spread by employing various strategies in the meantime., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 Elsevier Ltd. All rights reserved.)

In this work, we propose a new mathematical modeling of the spread of COVID-19 infection in an arbitrary population, by modifying the SIQRD model as m-SIQRD model, while taking into consideration the eight governmental interventions such as cancellation of events, closure of public places etc., as well as the influence of the asymptomatic cases on the states of the model. We introduce robustness and improved accuracy in predictions of these models by utilizing a novel deep learning scheme. This scheme comprises of attention based architecture, alongside with Generative Adversarial Network (GAN) based data augmentation, for robust estimation of time varying parameters of m-SIQRD model. In this regard, we also utilized a novel feature extraction methodology by employing noise removal operation by Spline interpolation and Savitzky-Golay filter, followed by Principal Component Analysis (PCA). These parameters are later directed towards two main tasks: forecasting of states to the next 15 days, and estimation of best policy encodings to control the infected and deceased number within the framework of data driven synergetic control theory. We validated the superiority of the forecasting performance of the proposed scheme over countries of South Korea and Germany and compared this performance with 7 benchmark forecasting models. We also showed the potential of this scheme to determine best policy encodings in South Korea for 15 day forecast horizon., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 Elsevier Ltd. All rights reserved.)

Interfaces in metal halide perovskite (MHP) solar cells cause carrier recombination and thereby reduce their power conversion efficiency. Here, ultrafast (picosecond to nanosecond) transient reflection (TR) spectroscopy has been used to probe interfacial carrier dynamics in thin films of the reference MHP MAPbI 3 and state-of-the-art (Cs 0.15 MA 0.15 FA 0.70 )Pb(Br 0.20 I 0.80 ) 3 (CsFAMA). First, MAPbI 3 films in contact with fullerene-based charge extraction layers (CTLs) in the presence and absence of LiF used as an interlayer (ITL) were studied. To quantify and discriminate between interface-induced and bulk carrier recombination, we employed a one-dimensional diffusion and recombination model. The interface-induced carrier recombination velocity was found to be 1229 ± 78 cm s -1 in nonpassivated MAPbI 3 films, which was increased to 2248 ± 75 cm s -1 when MAPbI 3 interfaced directly with C 60 , whereas it was reduced to 145 ± 63 cm s -1 when inserting a 1 nm thin LiF interlayer between MAPbI 3 and C 60 , in turn improving the open-circuit voltage of devices by 33 mV. Second, the effect of surface and grain boundary passivation by PhenHCl in CsFAMA was revealed. Here, the recombination velocity decreased from 605 ± 52 to 0.16 ± 5.28 and 7.294 ± 34.5 cm s -1 , respectively. The approach and data analysis presented here are immediately applicable to other perovskite/interlayer/CTL interfaces and passivation protocols, and they add to our understanding of the impact of surfaces and interfaces in MHP-based thin films on carrier recombination and device efficiency.

Solution-processed metal halide perovskite (MHP) single crystals (SCs) are in high demand for a growing number of printed electronic applications due to their superior optoelectronic properties compared to polycrystalline thin films. There is an urgent need to make SC fabrication facile, scalable, and compatible with the printed electronic manufacturing infrastructure. Here, a universal cosolvent evaporation (CSE) strategy is presented by which perovskite SCs and arrays are produced directly on substrates via printing and coating methods within minutes at room temperature from drying droplets. The CSE strategy successfully guides the supersaturation via controlled drying of droplets to suppress all crystallization pathways but one, and is shown to produce SCs of a wide variety of 3D, 2D, and mixed-cation/halide perovskites with consistency. This approach works with commonly used precursors and solvents, making it universal. Importantly, the SC consumes the precursor in the droplet, which enables the large-scale fabrication of SC arrays with minimal residue. Direct on-chip fabrication of 3D and 2D perovskite photodetector devices with outstanding performance is demonstrated. The approach shows that any MHP SC can now be manufactured on substrates using precision printing and scalable, high-throughput coating methods., (© 2022 Wiley-VCH GmbH.)

Neuromorphic computing has the potential to address the inherent limitations of conventional integrated circuit technology, ranging from perception, pattern recognition, to memory and decision-making ( Acc. Chem. Res. 2019, 52 (4), 964-974) ( Nature 2004, 431 (7010), 796-803) ( Nat. Nanotechnol. 2013, 8 (1), 13-24). Despite their low power consumption ( Nano Lett. 2016, 16 (11), 6724-6732), traditional two-terminal memristors can perform only a single function while lacking heterosynaptic plasticity ( Nanotechnology 2013, 24 (38), 382001). Inspired by the unconditioned reflex, multiterminal memristive transistors (memtransistor) were developed to realize complex functions, such as multiterminal modulation and heterosynaptic plasticity ( Nature 2018, 554, (7693), 500-504). Here we combine a hybrid metal halide perovskite with an organic conjugated polymer to form heterojunction transistors that are responsive to both electrical and optical stimuli. We show that the synergistic effects of photoinduced ion migration in the perovskite and electronic transport in the polymer layers can be exploited to realize memristive functions. The device combines reversible, nonvolatile conductance modulation with large switching current ratios, high endurance, and long retention times. Using in situ scanning Kelvin probe microscopy and variable-temperature charge transport measurement, we correlate the collective effects of bias-induced and photoinduced ion migration with the heterosynaptic behavior observed in this hybrid memtransistor. The hybrid heterojunction channel concept is expected to be applicable to other material combinations making it a promising platform for deployment in innovative neuromorphic devices of the future.

In bulk heterojunction (BHJ) organic solar cells (OSCs) both the electron affinity (EA) and ionization energy (IE) offsets at the donor-acceptor interface should equally control exciton dissociation. Here, we demonstrate that in low-bandgap non-fullerene acceptor (NFA) BHJs ultrafast donor-to-acceptor energy transfer precedes hole transfer from the acceptor to the donor and thus renders the EA offset virtually unimportant. Moreover, sizeable bulk IE offsets of about 0.5 eV are needed for efficient charge transfer and high internal quantum efficiencies, since energy level bending at the donor-NFA interface caused by the acceptors' quadrupole moments prevents efficient exciton-to-charge-transfer state conversion at low IE offsets. The same bending, however, is the origin of the barrier-less charge transfer state to free charge conversion. Our results provide a comprehensive picture of the photophysics of NFA-based blends, and show that sizeable bulk IE offsets are essential to design efficient BHJ OSCs based on low-bandgap NFAs.

The efficiency of state-of-the-art perovskite solar cells is limited by carrier recombination at defects and interfaces. Thus, understanding these losses and how to reduce them is the way forward toward the Shockley-Queisser limit. Here, we demonstrate that ultrafast transient absorption spectroscopy can directly probe hole extraction and recombination dynamics at perovskite/hole transport layer (HTL) interfaces. To illustrate this, we employed PDPP-3T as HTL because its ground-state absorption is at lower energy than the perovskite's photobleach, enabling direct monitoring of interfacial hole extraction and recombination. Moreover, by fitting the carrier dynamics using a diffusion model, we determined the carrier mobility. Afterwards, by varying the perovskite thickness, we distinguished between carrier diffusion and carrier extraction at the interface. Lastly, we prepared device-like structures, TiO 2 /perovskite/PDPP-3T stacks, and observed reduced carrier recombination in the perovskite. From PDPP-3T carrier dynamics, we deduced that hole extraction is one order faster than recombination of holes at the interface.

This study reports on the optoelectronic properties of porphyrin-based metal-organic framework (MOF) thin films fabricated by a facile liquid-phase epitaxy approach. This approach affords the growth of MOF thin films that are free of morphological imperfections, more suitable for optoelectronic applications. Chemical modifications such as the porphyrin ligand metallation have been found to preserve the morphology of the grown films making this approach particularly suitable for molecular alteration of MOF thin film optoelectronic properties without compromising its mesoscale morphology significantly. Particularly, the metallation of the ligand was found to be effective to tune the MOF bandgap. These porphyrin-based MOF thin films were shown to function effectively as donor layers in solar cells based on a Fullerene-C 60 acceptor. The ability to fabricate MOF solar cells free of a liquid-phase acceptor greatly simplifies device fabrication and enables pairing of MOFs as light absorbers with a wide range of acceptors including non-fullerene acceptors.

The reported power conversion efficiencies (PCEs) of nonfullerene acceptor (NFA) based organic photovoltaics (OPVs) now exceed 14% and 17% for single-junction and two-terminal tandem cells, respectively. However, increasing the PCE further requires an improved understanding of the factors limiting the device efficiency. Here, the efficiency limits of single-junction and two-terminal tandem NFA-based OPV cells are examined with the aid of a numerical device simulator that takes into account the optical properties of the active material(s), charge recombination effects, and the hole and electron mobilities in the active layer of the device. The simulations reveal that single-junction NFA OPVs can potentially reach PCE values in excess of 18% with mobility values readily achievable in existing material systems. Furthermore, it is found that balanced electron and hole mobilities of >10 -3 cm 2 V -1 s -1 in combination with low nongeminate recombination rate constants of 10 -12 cm 3 s -1 could lead to PCE values in excess of 20% and 25% for single-junction and two-terminal tandem OPV cells, respectively. This analysis provides the first tangible description of the practical performance targets and useful design rules for single-junction and tandem OPVs based on NFA materials, emphasizing the need for developing new material systems that combine these desired characteristics., Competing Interests: The authors declare no conflict of interest.

Background & Objective: Fractures of the distal radius are common with a variable prognosis in case of intra articular extension. The available options include Plaster, External fixation, Prefabricated Splintage using Ligamentotaxis, K-wire fixation, and open reduction internal fixation with T-plate without an as yet clear advantage of one over the others. If these fractures are allowed to collapse, radial shortening, angulation and articular incongruity may cause permanent deformity and loss of function. This limited small scale study was intended to compare the functional results of treatment of these fractures with a T plate and K-wires., Methods: This was a prospective experimental study conducted at department of Orthopedics of PGMI/Lahore General Hospital, Lahore. Total 30 patients were included and randomized into two groups of 15 patients each. Group-A patients were treated with Krischner's wires and Group-B patients were treated with a T-Plate with open reduction. Informed consent was taken. Post operative follow up was done for 12 weeks for the outcome parameters (Green and O'Brien score)., Results: Mean age of patients in Group-A and B was 36.13±9.81 and 44.73±7.86 years respectively. In Group-A there were 10 male and 5 female patients and in Group-B there were 8 male and seven female patients respectively. In Group-A nine patients presented with Fernandez type-II and six patients presented with Fernandez type-III fracture. While in Group-B 10 patients presented with Fernandez type-II and five patients presented with Fernandez type-III fracture. Among Group-A patient's final outcome was excellent in 86.67% patients while in Group-B only 53.33% patients had excellent outcome at three months follow up., Conclusion: Percutaneous Kirschner's wires appeared to be more effective as compared to T-Plate fixation in terms of functional outcome for treating intra-articular distal radius fractures., Competing Interests: Declaration of interest: None.

A breakthrough in the development of 4D scanning ultrafast electron microscopy is described for real-time and space imaging of secondary electron energy loss and carrier diffusion on the surface of an array of nanowires as a model system, providing access to a territory that is beyond the reach of either static electron imaging or any time-resolved laser spectroscopy., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Managing trap states and understanding their role in ultrafast charge-carrier dynamics, particularly at surface and interfaces, remains a major bottleneck preventing further advancements and commercial exploitation of nanowire (NW)-based devices. A key challenge is to selectively map such ultrafast dynamical processes on the surfaces of NWs, a capability so far out of reach of time-resolved laser techniques. Selective mapping of surface dynamics in real space and time can only be achieved by applying four-dimensional scanning ultrafast electron microscopy (4D S-UEM). Charge carrier dynamics are spatially and temporally visualized on the surface of InGaN NW arrays before and after surface passivation with octadecylthiol (ODT). The time-resolved secondary electron images clearly demonstrate that carrier recombination on the NW surface is significantly slowed down after ODT treatment. This observation is fully supported by enhancement of the performance of the light emitting device. Direct observation of surface dynamics provides a profound understanding of the photophysical mechanisms on materials' surfaces and enables the formulation of effective surface trap state management strategies for the next generation of high-performance NW-based optoelectronic devices., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Selective mapping of surface charge carrier dynamics of InGaN nanowires before and after surface passivation with octadecylthiol (ODT) is reported by O. F. Mohammed and co-workers on page 2313, using scanning ultrafast electron microscopy. In a typical experiment, the 343 nm output of the laser beam is used to excite the microscope tip to generate pulsed electrons for probing, and the 515 nm output is used as a clocking excitation pulse to initiate dynamics. Time-resolved images demonstrate clearly that carrier recombination is significantly slowed after ODT treatment, which supports the efficient removal of surface trap states., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

In the fields of photocatalysis and photovoltaics, ultrafast dynamical processes, including carrier trapping and recombination on material surfaces, are among the key factors that determine the overall energy conversion efficiency. A precise knowledge of these dynamical events on the nanometer (nm) and femtosecond (fs) scales was not accessible until recently. The only way to access such fundamental processes fully is to map the surface dynamics selectively in real space and time. In this study, we establish a second generation of four-dimensional scanning ultrafast electron microscopy (4D S-UEM) and demonstrate the ability to record time-resolved images (snapshots) of material surfaces with 650 fs and ∼5 nm temporal and spatial resolutions, respectively. In this method, the surface of a specimen is excited by a clocking optical pulse and imaged using a pulsed primary electron beam as a probe pulse, generating secondary electrons (SEs), which are emitted from the surface of the specimen in a manner that is sensitive to the local electron/hole density. This method provides direct and controllable information regarding surface dynamics. We clearly demonstrate how the surface morphology, grains, defects, and nanostructured features can significantly impact the overall dynamical processes on the surface of photoactive-materials. In addition, the ability to access two regimes of dynamical probing in a single experiment and the energy loss of SEs in semiconductor-nanoscale materials will also be discussed.

We explored for the first time the ultrafast carrier trapping of a metal-doped titanium dioxide (TiO2) semiconductor using broad-band transient absorption (TA) spectroscopy with 120 fs temporal resolution. Titanium dioxide was successfully doped layer-by-layer with two metal ions, namely tungsten and cobalt. The time-resolved data demonstrate clearly that the carrier trapping time decreases progressively as the doping concentration increases. A global-fitting procedure for the carrier trapping suggests the appearance of two time components: a fast one that is directly associated with carrier trapping to the defect state in the vicinity of the conduction band and a slow one that is attributed to carrier trapping to the deep-level state from the conduction band. With a relatively long doping deposition time on the order of 30 s, a carrier lifetime of about 1 ps is obtained. To confirm that the measured ultrafast carrier dynamics are associated with electron trapping by metal doping, we explored the carrier dynamics of undoped TiO2. The findings reported here may be useful for the implementation of high-speed optoelectronic applications and fast switching devices.

We demonstrated how the subcycle evolution of the electric field of light can be used to control the motion of bound electrons. Results are presented for the dissociative ionization of deuterium molecules (D2 --> D+ + D), where asymmetric ejection of the ionic fragment reveals that light-driven intramolecular electronic motion before dissociation localizes the electron on one of the two D+ ions in a controlled way. The results extend subfemtosecond electron control to molecules and provide evidence of its usefulness in controlling reaction dynamics.

This paper presents the performance analysis (capacity and retrieval accuracy) of multidimensional holographic associative memory (MHAC). MHAC has the unique ability to retrieve pattern-associations with changeable attention. In attention actuated retrieval the user can dynamically select any subset of the elements in the example query pattern and expect the memory to confine its associative match only within the specified field of attention. Existing artificial associative memories lack this ability. Also most of these models need at least 50% of bits in the input pattern to be correct for successful retrieval. MHAC, with the unique ability of localizable attention, can retrieve information correctly even with cues as small as 10% of the query frame. This paper investigates the performance of MHAC in attention actuated retrieval both analytically and experimentally. Besides confirmation, the experiments also identify an operational range space (ORS) for this memory within which various attention based applications can be built with a performance guarantee.

Over the last decade, suction-assisted lipoplasty has been shown to be a safe and reliable procedure in the hands of trained individuals. A large number of plastic surgeons employ liposuction as an adjunct to surgery for gynecomastia with excellent results and low morbidity. An unusual problem, traumatic rupture of the pectoralis major muscle, has been observed by us in a patient who had undergone the procedure. The physical deficit arising from the injury may go unnoticed in all but the most physically active people, and surgeons should be wary of the possibility of this previously unreported complication.

Paraffin impregnated tulle is frequently used as a post-operative dressing after surgical repair of wounds, on skin-donor sites and in packing of tissue cavities. Historically, paraffin has been injected into various sites of the body and paraffinoma is a well-described complication. Despite this, nasal packing with paraffin gauze is still common after rhinoplasty. We report a case of paraffinoma occurring after rhinoplasty and discuss the avoidance of this rare but serious complication and suggest silicon mesh as an alternative dressing.

This paper presents an associative technique for content-based retrieval into image archive, based on a computing paradigm called Multidimensional Holographic Associative Computing (MHAC). Unlike any prior Artificial Associative Memory (AAM), MHAC has the unique ability fo focus on any subject of pixels in the sample image and retrieve learned images based on the similarity of the visual objects. In addition, MHAC is adaptive, graciously accommodative of imprecision, efficient, parallelizable, scalable and optically realizable. Together, these excellent properties of MHAC offer a promising novel approach to a content-based search into massive image archives. The paper presents the necessary transformational steps to incorporate this new mechanism into a complete image archival and retrieval system. This is the first associative search approach for content-based retrieval in image repository. The results show that this search system is capable of retrievals by using pattern objects as small as 10-15% of the query image frame at better than 90% accuracy. This demonstrates the potential of MHAC for handing contest-based image applications far beyond the capability of current associative memories. The design, methodology and performance of this system have been illustrated in this paper through its application in managing a Medical Image Archive (MEDIA).

Hemangiomas and lymphangiomas remain the most common benign tumors seen by the plastic surgeon that involve a neonate's skin and deeper tissues. A significant number of tumors undergo spontaneous regression and require no treatment. The port wine stain (PWS) remains one of the most difficult variants of hemangiomas to treat and continues to be psychologically traumatic throughout a patient's lifetime. Recently, advanced use of laser technology has yielded beneficial results for a significant number of these patients. This report illustrates the incorporation of facelift surgery as an adjunct in the overall management of older patients resulting in decreased use of cosmetics and great improvement in general well being.

The Koebner phenomenon is an uncommon postburn complication. The following report describes the emergence of viral warts on the hand of a child, 6 months after sustaining a superficial scald. The aetiology and immunological implications are discussed.