Search

AbstractThe continual development of construction products is linked to the actors’ long-term persistent viability, capacity, and reputation involved in the construction process. If these businesses fail, the skills and expertise available to the construction industry today will be lost to future generations. One of the actors is Small and Medium Enterprises (SMEs) which play a crucial role in developing countries’ economies. Keeping this in view, this research aimed to identify the weakness and suggest the mechanisms for the effectiveness of the construction companies development programme in the Southern Regional State under the Universal Rural Road Access Program (URRAP). Besides the URRAP program design document analysis, a desktop study on contractor development programmes of six African countries’ practices was conducted for comparison. The program’s design document lacked: specific detailed objectives on methodology and a detailed time-frame to achieve construction company development, business and management-related training, holistic development addressing all of the essential issues, and supporting financial institutions for access to credit and financing. For developing URRAP construction enterprises, there is a felt need to create a conducive business environment, and improve access to work opportunities, training and advisory services, and programme structure, such as support initiatives, should be planned and implemented.

This article presents a novel complex fractional order (CFO) speed controller design and its implementation on an induction motor (IM) drive. This controller with multiple dimensions of control parameters as compared with existing industrial controllers provides more robust performance under variable operating conditions. Mostly, detuning of the existing controllers under varying operating parameters has limited bandwidth tolerance in low speed operation and temperature dependent circuit parameters, which is enhanced by the CFO controllers. A frequency domain design methodology for the CFO speed controller is incorporated with the fractional order (FO) nature of voltage source inverter fed IM. The realistic FO-IM transfer function model identification is provided with the chirp signal injection method. Within the designed bandwidth of a CFO speed controller, the surface curve fitting-based approximation technique provides ease in its implementation. The stator resistance variation up to 150% of nominal value and the rotor inertia variation up to eight times of the no-load value is tested to verify the performance under dynamic operating conditions. Under the same stability boundary limits, the results show the superiority of the CFO controller performance over FO proportional integral and integer order proportional integral controllers. On the hardware-in-loop system, the experimental validation of these controllers is performed.

The practical applicability of the single-phase $( {1\emptyset } )$ power supplied conventional single-stage matrix converter (SSMC) to synthesize multiphase $( {m\emptyset } )$ power is limited to very low frequency (3–5 Hz) output. In this article, a modified SSMC is proposed for $1\emptyset \ to\ m\emptyset $ conversion which can extensively operate to derive the output frequency up to half of the rated supply frequency and ensures balanced operation with better power quality across the supply as well as load side. The proposed SSMC has three branches each constitute of an array of bidirectional switches supplied by a $1\emptyset $ source through a filter circuit of one inductor and two capacitors. This configuration of the proposed SSMC makes it suitable to synthesize $m\emptyset $ output from the available $1\emptyset $ power supply from very low output frequency to maximum frequency equals to half of the rated supply frequency while maintaining supply side unity power factor and standard voltage transfer ratio. Experimental results are presented to validate the performance of the proposed SSMC for $1\emptyset \ to\ m\emptyset $ conversion.

Children with chronic neuromuscular conditions (CCNMC) have many coexisting conditions and often require musculoskeletal surgery for progressive neuromuscular scoliosis or hip dysplasia. Adequate perioperative optimization may decrease adverse perioperative outcomes. The purpose of this scoping review was to allow us to assess associations of perioperative health interventions (POHI) with perioperative outcomes in CCNMC.Eligible articles included those published from January 1, 2000 through March 1, 2022 in which the authors evaluated the impact of POHI on perioperative outcomes in CCNMC undergoing major musculoskeletal surgery. Multiple databases, including PubMed, Embase, Cumulative Index of Nursing and Allied Health Literature, Web of Science, the Cochrane Library, Google Scholar, and ClinicalTrials.gov, were searched by using controlled vocabulary terms and relevant natural language keywords. Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews guidelines were used to perform the review. A risk of bias assessment for included studies was performed by using the Risk of Bias in Non-randomized Studies of Interventions tool.A total of 7013 unique articles were initially identified, of which 6286 (89.6%) were excluded after abstract review. The remaining 727 articles’ full texts were then reviewed for eligibility, resulting in the exclusion of 709 (97.5%) articles. Ultimately, 18 articles were retained for final analysis. The authors of these studies reported various impacts of POHI on perioperative outcomes, including postoperative complications, hospital length of stay, and hospitalization costs. Because of the heterogeneity of interventions and outcome measures, meta-analyses with pooled data were not feasible.The findings reveal various impacts of POHI in CCNMC undergoing major musculoskeletal surgery. Multicenter prospective studies are needed to better address the overall impact of specific interventions on perioperative outcomes in CCNMC.

This paper presents a new nonlinear fractional-order model identification of a two-level voltage source inverter fed induction motor (VSI-IM). The nonlinearities present in inverter and IM cause the failure of the sensorless controls and model predictive controls, which mainly depends on the VSI-IM model. In the proposed work, an attempt has been made to identify the exact nonlinear behavior of the VSI-IM model using the PWM signal injection method. The identified fractional-order VSI-IM model is helpful to provide more insight into the dynamic behavior of the IM drive in the speed controller design (sensorless and sensored) and in predictive controls (model-based and model-free). The fractional VSI-IM models are identified at low, medium, and high frequencies. The best fit of these models is compared to the integer-order identified VSI-IM models. The experimental study clearly shows that the fractional-order VSI-IM identified model is superior to the integer-order VSI-IM model in terms of best fit with the actual hardware speed response.

The nonisolated multi-input topologies are restricted to low voltage gain relative to single-input topologies. To achieve high voltage gain, coupled inductor, and various voltage-boosting techniques (such as switched inductors/capacitors) are used in the literature. The voltage-boosting structures increase the total component count, size, and cost of the converter. The operational limitations are observed in coupled-inductor-based converters due to peak current at a source side. This work proposes a nonisolated integrated boost featured converter without using a coupled inductor and voltage-boosting techniques. It achieves ultrahigh voltage gain with three basic boost cells, over other reported converters in a two-input category, with less component count and low average normalized voltage stress. It also facilitates flexible operating possibilities such as single-input, multi-input, and energy transfer capability among input ports. Furthermore, with equal duty cycle control ($D_{1}=D_{2}=D_{3}$), the power management between the energy storage systems is inherently provided by the proposed topological structure. The control complexity is minimized in a modified control algorithm. Hence, the integration of various energy storage systems is simplified. A hardware prototype is developed to validate the functional capability of the proposed converter.

In this article, a novel Euclidean distance mapping (EDM) technique for space vector pulse width modulated (SVPWM) voltage source inverter (VSI) is presented. The EDM technique processes space vector diagram (SVD) as an image, which simplifies execution of SVPWM. In the proposed technique, Euclidean distance calculation between all eight switching vectors and the tip of the revolving reference voltage vector for every subcycle is carried out. The identification of nearest three voltage vectors (NTV) and switching sequence designs are done on the basis of these Euclidean distances. The EDM-SVPWM technique achieves improvement in the inverter performance in the context of the factors like stator flux ripple over a subcycle, distortion factor (DF), total harmonics distortion (THD) of line voltage, and line current ripple of the inverter. The performance of EDM-SVPWM technique is verified analytically and confirmed experimentally by hardware implementation over the wide range of fundamental frequencies and modulation indices.

The control performance of induction motor (IM) drive is related to its accurate identified transfer function model. Fractional order transfer function (FOTF) identification of the realistic world dynamics is necessary to get the desired performance. In this article, six-phase IM FOTF is accurately identified using dual-chirp signal excitation in current control loop of field oriented control (FOC) IM structure. The model identification based on the parameters such as speed and current measured with chirp signal excitation provides FOTF. The frequency-domain identification approach uses an estimated state space model having fractional order (FO) coefficients with square error minimization. The identification results are in a close realization with the actual speed response obtained; moreover, a comparison has been performed to infer the actual hardware magnitude response using integer order and fractional order models. This FO identification model of six-phase IM is found to be more accurate in speed open-loop and current closed loop in consideration of frequency-domain error index and best fit.

Graphical abstract:

A single-stage matrix converter (MC) is preferred for the conversion of a single-phase $({1\emptyset })$ supply of fundamental frequency (50 Hz) to the multiphase $({m\emptyset })$ power supply in a limited operating frequency range (5–15 Hz). These converters possess a limitation on account of voltage and current distortions when the converter is used up to fundamental or higher frequency operating loads. To resolve this problem, this letter proposes a dual-stage $1\emptyset \ \text{to}\ m\emptyset $ MC, which ensures improved power quality across the output voltage and current. This converter has a three-leg front-end side rectifier stage (RS) consisting of six numbers of common emitter configured bidirectional power semiconductor switches. A filter circuit is installed in between $1\emptyset $ supply and RS enabling to build positive average dc voltage across the virtual dc link while maintaining the source current profile. The second stage is an inversion stage having a conventional voltage source inverter structure. The proposed dual-stage MC topology is having a simple structure with the ability to convert the $1\emptyset $ supply to any number of desired output phases not only at the lower frequency but also at the fundamental and higher frequency. The practical applicability of the proposed dual-stage MC is validated through experimental results.

This brief describes the two unique Fractional Order (FO) speed controllers’ FOPI and FO[PI] design and validation for the induction motor drive. The detuning of the conventional PI controller issues under machine parameter variations and low speed operating regions are overcome by the proposed two types of FO speed controllers. This brief presents the novel FO controller design procedure for the Voltage Source Inverter (VSI) fed IM. The actual FO VSI fed IM transfer function model is identified using the chirp signal injection method with the Hardware-In-Loop (HIL) system for the laboratory prototype. The parameter variation is subjected to different stator winding resistance machines of the same rating. The rotor inertia change of up to eight times the no-load value is incorporated to investigate the robust performance of these speed controllers under dynamic operating conditions. The performance of the designed $FOPI$ and $FO[PI]$ controllers are analyzed at low speeds. The results show the supremacy of the $FO[PI]$ controller over the $FOPI$ and PI under the same stability boundary limits. The experimental validation of these controllers is provided.

AbstractSickle cell disease (SCD) is a major medical problem in which mono-therapeutic interventions have so far shown only limited effectiveness. We studied the repurpose of genistein, which could prevent sickle hemoglobin from polymerizing under hypoxic conditions in this disease. Genistein an important nutraceutical molecule found in soybean. The present study examines the repurposing genistein as an anti- sickling agent. Genistein shows inhibition of Hb S polymerization as well as a sickle reversal. Also, we have explored the interaction of the genistein with sickle hemoglobin (Hb S), using fluorescence, far-UV-CD spectroscopy, MicroScale Thermophoresis (MST), FTIR, combined with molecular modeling computations. The quenching constant decreases with increasing temperature, a characteristic that coincides with the static type of quenching mechanism. Temperature-dependent fluorescence measurements and molecular modeling studies reveal that apart from the hydrogen bonding, electrostatic interactions also play a crucial role in genistein and Hb S complex formation. In silico, distribution prediction of adsorption, digestion, metabolism, excretion, and toxicity (ADME/Tox) based on physical and chemical properties show that genistein is nontoxic and has ideal drug properties. The helicity and thermophoretic mobility of Hb S was a change in the presence of genistein, which leads to the destabilizing the Hb S polymer was examined using CD and MST, respectively. Our results open up the possibility for a promising therapeutic approach for the SCD by repurposed genistein as an anti-sickling agent.Communicated by Ramaswamy H. Sarma

Graphical Abstract:

In response to the growing demand for sustainable graphene synthesis methods, traditionally characterized by harsh conditions and prolonged processing, we present an innovative approach. Here, graphene is synthesized utilizing melaleuca alternifolia, a natural resource, under mild conditions of cold plasma. This method not only aligns with the increasing need for environmentally friendly processes but also boasts efficiency, producing graphene within seconds. Our investigation employs various analytical techniques, including Raman spectroscopy, confirming the successful synthesis of graphene. The distinctive peaks identified in the spectroscopic analysis validate the high quality of the graphene material produced. Beyond synthesis, our study delves into the electrochemical properties of the synthesized graphene. Rigorous testing with real biomolecules reveals enhanced current peaks, underscoring the potential applications of graphene in the realm of electrochemical sensing. This work contributes to advancing sustainable and efficient graphene synthesis while exploring its promising properties for practical applications.

Single-step, single-precursor synthesis of nitrogen-doped graphene oxide (N-GO) was demonstrated in this work. By choosing aniline as the sole source of carbon and nitrogen, N-GO films were fabricated using microwave plasma at a power as low as 80 W in atmospheric conditions. The aniline vapor dissociated under plasma formed islands of N-GO nanosheets on the substrates or walls of the quartz deposition chamber. The interplanar spacing in the pristine N-GO films was observed to be lower than that of GO films, which indicated a lower concentration of oxygen and other species present in the space between the N-GO layers. The as-fabricated N-GO demonstrated superior antiscaling and algicidal properties that are deemed imperative for water purification applications.

Gait analysis in the pediatric and adult orthopedic patient populations can adjunct the diagnosis and treatment of a multitude of musculoskeletal conditions. Understanding of normal and abnormal gait biomechanics is an important aspect of orthopedic residency; yet, there is great variability in the time residency programs dedicate to gait analysis education. The purpose of this study was to investigate if formal gait analysis education during residency improves an orthopedic resident’s understanding of normal and pathologic gait. Five residency programs consisting of 81 resident subjects were surveyed at the beginning of the 2016–2017 academic year. The residents were divided into those with formal gait analysis education (group A) and those without (group B). Each resident was sent an online survey with 11 questions from former orthopedic in-training exams (OITE) regarding gait pattern analysis. The average number of correct questions was compared between the two groups with Student’s t-test. Fifty-three of the 81 surveys sent out were completed. There were 23 subjects in group A and 30 in group B. All five programs and all postgraduate years (PGYs) were represented (PGY1: 10, PGY2: 12, PGY3: 12, PGY4: 6, PGY5 12). The average score for all residents was 5.6 out of 11 correct (51%). The residents from group A averaged a significantly higher score (6.3) than group B (5.0) (P= 0.017). Understanding gait biomechanics is a critical skill for orthopedic surgeons, and residency training often lacks sufficient training in their curriculum. A good understanding of gait analysis allows orthopedic surgeons to analyze gait disturbances and develop patient-specific treatment plans in adult and pediatric populations. This study found improved knowledge of gait patterns amongst orthopedic residents with formal education. Even though the residents with formal education fared better than their counterparts, the overall percent correct was still low (51%). Evidence: Level 3: Prospective Cohort Study.

Supplemental Digital Content is available in the text.

Purpose: We earlier reported that Sestrin2 regulates monocyte activation and atherogenic events through AMPK-mTOR nexus under high-glucose and dyslipidemic conditions. However, the statuses of Sestrins in diabetes and dyslipidemia are not known. We report here on the status of Sestrins and their association with diabetic dyslipidemia and atherosclerosis. Methods: Individuals with normal glucose tolerance (NGT) (n= 46), dyslipidemia (n= 42), and patients with Type 2 diabetes with (n= 41) and without dyslipidemia (n= 40) were recruited from a tertiary diabetes centre, Chennai, India to study the mRNA expression levels of Sestrins (1, 2, and 3) in monocytes by RT-qPCR. Serum levels of Sestrins were measured using ELISA. Atherogenic index of plasma was calculated as log (triglyceride/HDL). Results: mRNA expressions of Sestrin1 and Sestrin3 were significantly reduced in monocytes under dyslipidemic conditions but not in diabetes condition. Interestingly, Sestrin2 mRNA expression was significantly reduced in all disease conditions including dyslipidemia, and diabetes with and without dyslipidemia. Sestrin2 mRNA levels were negatively correlated with glycemic and lipid parameters and plasma atherogenic index. Furthermore, circulatory Sestrin2 was also found to be significantly decreased in dyslipidemia (415.2 ± 44.7 pg/ml), diabetes (375 ± 45 pg/ml), and diabetes with dyslipidemia (319.2 ± 26.3 pg/ml) compared to NGT (706.3 ± 77 pg/ml) and negatively correlated with glycemic, lipid parameters, and plasma atherogenic index. Conclusion: We report for the first time that Sestrins levels are significantly decreased in diabetes and dyslipidemic conditions. More strikingly, Sestrin2 had a strong association with atherogenic risk factors and severity of atherogenic index and we suggest that Sestrin2 may be used as a biomarker for assessing atherogenesis.

This paper explores whether employee commitment to the organisation is influenced by talent acquisition and retention practices. How do SMEs retain talent and encourage commitment and job embedding when their very existence is in doubt? The talk these days is about layoffs, terminations, reduced pay, no-pay leave and redeployment; how will SMEs fare in this scenario? This qualitative study includes in-depth interviews conducted using a social constructivism approach in order to gain a better understanding of the world in which we live and work. Individual meanings are formed not entirely within the individual, but through interaction with others, the social, where meaning is given. The template analysis method is used to analyse the interviews, which include specific themes. The findings point to a misalignment between talent acquisition, talent retention practices and organisational commitment. There has been no clear development in terms of how both can complement each other. As a result, the dimensions of person-organisation and person-job fit serve as a link between talent acquisition, retention and commitment. This contributes to higher levels of employee commitment, job embeddedness and an internal culture that may influence employee retention decisions. At the interpersonal level, SME owners must understand, nurture and motivate their talent. As an effective employee retention tool, monetary incentives play only a minor role. Talent retention is based on implementing a structured talent acquisition practice that includes a highly targeted cost-effective hiring plan. Talent acquisition includes fit dimensions that demonstrate a nuanced perception of individualised consideration, such as flexible work, belonging, career growth and interpersonal relationships.

[Display omitted]

Purpose: The purpose of this study was to evaluate the peri-operative outcomes of patients with Prader–Willi Syndrome (PWS) undergoing spinal deformity correction and compare the outcomes to patients with adolescent idiopathic scoliosis (AIS). Methods: A retrospective review of the Kid’s Inpatient Database was performed from 2000 to 2012 to identify all pediatric patients with scoliosis undergoing spinal fusion. Cohorts were created on the basis of PWS diagnosis and adolescent idiopathic scoliosis. Statistical analysis was performed for differences in post-operative outcomes between these two patient cohorts. Results: Between 2000 and 2012, the number of spinal fusions performed increased by 24.6 and 32.2% in the PWS and adolescent idiopathic scoliosis populations, respectively. There was no difference between the incidence of major complications in PWS patients when compared to AIS (1.7% vs. 1.0% in idiopathic scoliosis; p= 0.362). Although there was no significant difference in the rate of overall minor complications, PWS patients were demonstrated to be more likely to experience post-operative pneumonia (p< 0.0001) and implant complications (p< 0.001). Conclusion: Patients with scoliosis associated with PWS do not have any increased risk of major complications following spinal deformity correction when compared to patients with adolescent idiopathic scoliosis. Two important minor complications to keep in mind when surgically treating scoliosis in PWS patients include pulmonary and implant-related complications. Level of evidence: Retrospective comparative study, Level III.

The predictive torque control (PTC) is researched extensively for control of electrical drives because of its fast-dynamic response and robust control. In multiphase motors, it is mandatory to design a multiobjective cost function with more than two terms for controlling $x\!y$ -subspace current and common-mode voltage (CMV). However, selecting the weighting factor for multiple control variables is time penalizing and increases the computational burden. Using a noisy speed input from the speed sensor in the prediction model reduces the steady-state performance in terms of higher torque ripple, flux ripple, and phase current total harmonic distortion (THD), especially during low speeds. In this article, PTC for a five-phase induction motor (IM) drive without speed sensor [sensorless PTC (PTC-S)] is presented. The adaptive full observer is incorporated to estimate the stator flux, stator resistance, and rotor speed. The proposed algorithm is capable to eliminate CMV and $x\!y$ -current harmonics having advantages over the conventional PTC (PTC-C) algorithm. The elimination of CMV is achieved by the selection of set of voltage vectors from available 243 voltage vectors. The proposed speed sensor-less control is implemented with a three-level neutral-point clamped (NPC) inverter using synthetic voltage vectors. The use of a synthetic voltage vector eliminates the $x\!y$ -subspace current and reduces the computational burden. The PTC-S is implemented with a seven-level hysteresis torque comparator, which reduces the torque ripple significantly. To further improve the effectiveness of the control algorithm, two-step delay compensation is implemented. The discussed algorithms are tested on a laboratory prototype for experimental evaluation. The proposed study also highlights the effect of torque ripple reduction on the speed adaptive flux observer for sensor-less operation. The experimental results show the effectiveness and applicability by comparing the steady-state and dynamic performances of PTC.

Marine biofouling remains one of the key challenges for maritime industries, both for seafaring and stationary structures. Currently used biocide-based approaches suffer from significant drawbacks, coming at a significant cost to the environment into which the biocides are released, whereas novel environmentally friendly approaches are often difficult to translate from lab bench to commercial scale. In this article, current biocide-based strategies and their adverse environmental effects are briefly outlined, showing significant gaps that could be addressed through advanced materials engineering. Current research towards the use of natural antifouling products and strategies based on physio-chemical properties is then reviewed, focusing on the recent progress and promising novel developments in the field of environmentally benign marine antifouling technologies based on advanced nanocomposites, synergistic effects and biomimetic approaches are discussed and their benefits and potential drawbacks are compared to existing techniques.

The International Air Transport Association (IATA) reports that the impact of COVID-19 translates into a $630 billion reduction in tourism and travel related GDP and over 26 million job loss. This study examines how innovation influences company performance within the global airline industry covering the periods 2000 to 2020. Several fixed and random effect models and system-GMM approaches were employed. The findings indicate that higher investment in innovation helps increase profit margin and return on equity but reduces return on assets. Higher return from product development expenses (higher product development expenses) increases (decreases) profitability and efficiency of the company. Also, higher product development expense and profitability nexus indicates that companies may have to rely heavily on internal capital while financing for research and development (R&D). While national bailouts, mergers, climate change related sustainability agendas will be issues as airlines get back on slowly with the gradual opening of economies and vaccine miracle, the findings reported in this paper will bear significant policy implications for the sector overall.

Idiopathic clubfoot is the most common congenital anomaly of the lower extremity. YouTube has emerged as an important source of health-related information for patients and families. Parents seek information about clubfoot on YouTube. However, the quality of these videos remains unknown. Therefore, we decided to evaluate the quality of YouTube videos about clubfoot. We searched YouTube for clubfoot videos using appropriate keywords. English language videos with more than 10 000 views were included. Three fellowship trained pediatric orthopedic surgeons independently assessed the videos and classified them into corporate, hospital, education and private. The quality of information was assessed using the Modified DISCERN and JAMA benchmark scores. The search yielded 12 060 videos of which 42 were analyzed. There were 9 (21%) videos from corporate organizations, 12 (29%) from hospitals, 3 (7%) from educational organizations and 18 (43%) by private individuals. The mean Modified DISCERN score was 2.1 ± 1.07 (range 0.3–4) and mean JAMA benchmark score was 0.9 ± 0.65 (range 0–2). Educational videos had highest mean Modified DISCERN score (3.1 ± 0.85) and private videos, the least (1.43 ± 1). This difference was statistically significant (P = 0.004). Hospital videos had highest mean JAMA benchmark score of 1.3 ± 0.6 as compared with private videos which had the least mean score of 0.5 ± 0.6. This difference was also statistically significant (P = 0.001). The results of our study indicate that the quality of information on idiopathic clubfoot on YouTube needs improvement. Videos from educational and hospital sources should be preferred over private sources.

Graphene and its derivatives have acquired substantial research attention in recent years because of their wide range of potential applications. Implementing sustainable technologies for fabricating these functional nanomaterials is becoming increasingly apparent, and therefore, a wide spectrum of naturally derived precursors has been identified and reformed through various established techniques for the purpose. Nevertheless, most of these methods could only be considered partially sustainable because of their complexity as well as high energy, time, and resource requirements. Here, we report the fabrication of carbon nano-onion-interspersed vertically oriented multilayer graphene nanosheets through a single-step, environmentally benign radio frequency plasma-enhanced chemical vapor deposition process from a low-cost carbon feedstock, the oil from the peel of Citrus sinensisorange fruits. C. sinensisessential oil is a volatile aroma liquid principally composed of nonsynthetic hydrocarbon limonene. Transmission electron microscopy studies on the structure unveiled the presence of hollow quasi-spherical carbon nano-onion-like structures incorporated within graphene layers. The as-fabricated nano-onion-incorporated graphene films exhibited a highly hydrophobic nature showing a water contact angle of up to 1290. The surface energies of these films were in the range of 41 to 35 mJ·m–2. Moreover, a chemiresistive sensor directly fabricated using C. sinensis-derived onion-structured graphene showed a p-type semiconductor nature and a promising response to acetone at room temperature. With its unique morphology, surface properties, and electrical characteristics, this material is expected to be useful for a wide range of applications.

AbstractSickle cell disease is an inherited disease caused by point mutation in hemoglobin (β-globin gene). Under oxygen saturation, sickle hemoglobin form polymers, leading to rigid erythrocytes. The transition of the blood vessels is altered and initiated by the adhesion of erythrocytes, neutrophils and endothelial cells. Sickle Hemoglobin (HbS) polymerization is a major cause in red blood cells (RBC), promoting sickling and destruction of RBCs. Isoquercitrin, a medicinal bioactive compound found in various medicinal plants, has multiple health benefits. The present study examines the potential of isoquercitrin as an anti-sickle agent, showing a significant decrease in the rate of polymerization as well as sickling of RBCs. Isoquercitrin-induced graded alteration in absorbance and fluorescence of HbS, confirmed their interaction. A negative value of ΔG° strongly suggests that it is a spontaneous exothermic reaction induced by entropy. Negative ΔH° and positive ΔS° predicted that hydrogen and hydrophobic binding forces interfered with a hydrophobic microenvironment of β6Val leading to polymerization inhibition of HbS. HbS-Isoquercitrin complex exhibits helical structural changes leading to destabilization of the HbS polymer as confirmed by CD spectroscopy. MST and DSC results indicate greater changes in thermophoretic mobility and thermal stability of sickle hemoglobin in the presence of isoquercitrin, respectively. These findings were also supported by molecular simulation studies using DOCK6 and GROMACS. Hence, we can conclude that isoquercitrin interacts with HbS through hydrogen bonding, which leads to polymerization inhibition. Consequently, isoquercitrin could potentially be used as a medication for the treatment of sickle cell disease.Communicated by Ramaswamy H. Sarma

AbstractIn this study, four textural classes of soil (Clay, Clay Loam, Loam, and Loamy Sand) were used to investigate the dielectric properties of soils, using a vector network analyser with an open-ended coaxial probe kit at room temperature (25 ± 2°C) in the 700–7000 MHz microwave frequency range. Four levels of soil moisture content (oven dry, 33% field capacity, 66% field capacity and 100% field capacity) were maintained to perform the experiment with three replication and three observation each. The results showed that, with increasing soil moisture, from oven dry conditions to 100% field capacity, both the real (Dielectric Constant) and imaginary (Loss Factor) components of the dielectric properties increased; however, the responses were not linear. The dielectric properties of oven dry soils were very low compared with the soils with higher moisture content. Therefore, soil moisture was the major contributor to the dielectric behaviour of soil. The dielectric properties of sandy soil were much lower than the other soils; however, the dielectric loss factor of the Dookie clay soil was higher compare with the other soils. Models were developed to explain the dielectric properties of soils as a function of frequency and moisture content. The goodness of fit (r2) for these models varies between 0.952 for the Dookie Sandy Soil to 0.997 for the Dookie Loam Soil, suggesting that these models were adequate to describe the dielectric properties of these soils over the range of frequencies and moisture contents assessed in this study. Another model was developed to estimate the expected penetration depth of electromagnetic waves in these soils, based on the model of the dielectric properties. It was clear that penetration decreases with both frequency and moisture content. Low frequencies penetrate further into the soils than higher frequencies. Similarly, dry soils allow further penetration than moist soils.

AbstractPolymerization of hemoglobin S is a major cause of morbidity and mortality in sickle cell disease, which leads to sickling and destruction of red blood cell. Alizarin, a bioactive compound from Rubia cordifolia, is reported to be blood purifier. This study investigates the potential of alizarin as an anti-sickling agent, showing a significant decrease in the rate of polymerization, therefore inhibiting the rate of sickling with increasing concentration. Interaction studies indicated that the fluorescence intensity of sickle hemoglobin (Hb S) decreases gradually with increasing alizarin concentration. This suggests the static quenching, where binding constant and the number of binding sites were deduced at different temperatures. The negative values of Gibbs energy change (ΔG0) strongly suggest that it is entropy-driven spontaneous and exothermic reaction. Negative enthalpy (ΔH0) and positive entropy (ΔS0) stipulated that hydrogen and hydrophobic bonding forces were interfering in a hydrophobic micro-environment of β6Val leading to Hb S polymerization inhibition. In circular dichroism (CD) spectra, Hb S in the presence of alizarin shows helical structural changes leading to destabilization of Hb S polymer. These findings were also supported by molecular docking simulation studies using DOCK6 and GROMACS. So, from these findings, we may conclude that alizarin interacts with Hb S through hydrogen bonding and leading to inhibition of Hb S polymerization. Consequently, alizarin may have potential use as an anti-sickle cell medication for sickle cell disorder.Communicated by Ramaswamy H. Sarma

Metal-organic frameworks (MOFs), due to its exceptional characteristics like high specific surface area and design diversity, serve as an outstanding sacrificial template in forming layered double hydroxides (LDHs) for highly efficient electrodes in supercapattery devices. In this work, we have prepared bimetallic layered Nickel Cobalt LDH via in-situ etching of Co-ZIF, in different Nickel concentrations directly on Ni foam that enhances the interfacial contact between substrate and the material. The optimised NiCo LDH-2 sample exhibited remarkable electrochemical behaviour with fast electrolyte ion diffusion kinetics ideal for supercapattery device and delivered a high specific capacitance of 2567 Fg−1at 1 Ag−1. Further, the supercapattery device assembled with Ni-Co LDH as anode and rGO derived from a sustainable source as cathode demonstrated an energy density of 21 Whkg−1, power density of 0.307 kWkg−1and good cyclic stability with capacitance retention of 88.89 % along with coulombic efficiency of 90.58 % over 1500 cycles. This work proposes an effective approach for designing layered NiCo-LDH that can be further extended to the synthesis of other transition metal-derived LDH for supercapattery devices.