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1.
Pediatr Nephrol ; 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38822220

RESUMO

BACKGROUND: Levamisole is less expensive and has a better toxicity profile compared to other steroid sparing agents used in nephrotic syndrome. It has a plasma half-life of 2.0 to 5.6 hours, but is conventionally administered on alternate days. We aimed to assess whether daily levamisole is safe and more effective than standard alternate-day therapy in maintaining remission in children with frequently relapsing or steroid-dependent nephrotic syndrome (FR/SDNS). METHODS: An open-label randomized controlled trial was conducted in children with FR/SDNS. Group A received daily while Group B received alternate-day levamisole (2-3 mg/kg/dose) for 12 months. Prednisolone was tapered off by 3 months. Patients were monitored for relapses, further steroid requirement, and adverse effects. RESULTS: A total of 190 children with FR/SDNS (94 in Group A and 96 in Group B) were analyzed. Sustained remission for 12 months was observed in 36% of Group A and 27% of Group B patients (p = 0.18). Numbers completing 12 months in the study were 67% in Group A and 56% in Group B (p = 0.13). Time to first relapse, persistent FR/SDNS, and withdrawal due to poor compliance were statistically similar in both groups, while relapse rate and cumulative steroid dosage were significantly lower in Group A compared to Group B (p = 0.03 and p = 0.02, respectively). The incidence of adverse effects was comparable in both groups, with reversible leucopenia and hepatic transaminitis being the commonest. CONCLUSIONS: Daily levamisole therapy was not superior to alternate-day therapy in maintaining sustained remission over 12 months. Nevertheless, relapse rate and cumulative steroid dosage were significantly lower without increased adverse effects.

2.
Pediatr Nephrol ; 39(8): 2423-2427, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38589697

RESUMO

BACKGROUND: Levamisole is a commonly used steroid-sparing agent (SSA), but the reported incidence of antineutrophil cytoplasmic antibody (ANCA) positivity has been concerning. METHODS: Observational cross-sectional study wherein children aged 2 to 18 years with frequently relapsing/steroid dependent nephrotic syndrome (FRNS/SDNS) on levamisole for ≥ 12 months were tested for ANCA. RESULTS: A total of 210 children (33% female), median age of 7.3 (IQR: 5.6-9.6) years, and a median duration of levamisole exposure of 21 (IQR: 15-30) months were tested. ANCA was positive in 18% (n = 37): 89% (n = 33) perinuclear ANCA (pANCA), 3% (n = 1) cytoplasmic ANCA (cANCA), and 8% (n = 3) both. Of ANCA-positive children, none had reduced eGFR or abnormal urinalysis. The majority of these children were asymptomatic (81%, n = 30). Rash was more common among ANCA-positive children [6/37 (16%) vs. 3/173 (2%), p = 0.0001]. On multivariate analysis, higher age (OR = 1.02, [95th CI: 1.01 to 1.03], p = 0.007) and longer duration of levamisole exposure (OR = 1.05, [95th CI: 1.02 to 1.08], p = 0.0007) were associated with ANCA positivity. Levamisole was stopped in ANCA-positive children with the resolution of any clinical manifestations if present. Repeat ANCA testing was performed in 54% (20/37), and all were ANCA negative by 18 months. CONCLUSIONS: Children with FRNS/SDNS on longer duration of levamisole were associated with increasing prevalence of ANCA positivity, but most of these children were clinically asymptomatic. Prospective studies are required to determine the chronology of ANCA positivity and its clinical implication.


Assuntos
Anticorpos Anticitoplasma de Neutrófilos , Levamisol , Síndrome Nefrótica , Humanos , Levamisol/efeitos adversos , Criança , Feminino , Masculino , Estudos Transversais , Anticorpos Anticitoplasma de Neutrófilos/sangue , Anticorpos Anticitoplasma de Neutrófilos/imunologia , Síndrome Nefrótica/tratamento farmacológico , Síndrome Nefrótica/imunologia , Síndrome Nefrótica/sangue , Pré-Escolar , Adolescente , Estudos de Coortes
3.
ISA Trans ; 146: 336-351, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38278757

RESUMO

Existing feedforward, or FF, controllers are based on differentially flat models. For double-acting single-rod cylinders, more compact than the double-rod ones, flat models could be constructed either under an incompressible-flow assumption for low-pressure, slow-response applications or for a matched valve-cylinder combination. Contrasting the existing models tackling only a single nonlinear aspect like valve leakage, oil compressibility or friction, a novel FF controller, generalized for different types of valve-cylinder-pump combinations, has been developed here. It is based on the highest-order assumption of incompressible flow that sustains the piston motion. An FFPI controller has been implemented in a laboratory setup for displacement tracking against sinusoidal demands up to 9 Hz frequency. The FF parameters has been estimated by minimizing the deviation of simulation prediction from an offline experimental time-varying response. The PI gains have been selected through a stability analysis by extending Routh criteria for linearized time-variant error dynamics. Comparison against a PI-only controller with identical gains has established the energy-saving potential of the FFPI controller both working with the same variable-displacement pump. In comparison to existing nonlinear adaptive controllers, more precise and smoother responses have been obtained over wider frequency range at lower control expenses, admittedly with occasional marginal penalty in the phase variation. The FFPI controller has exhibited the shortest transient and the highest resilience against measurement noise.

4.
Org Lett ; 25(40): 7310-7315, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37791996

RESUMO

A one-pot, regioselective decarboxylative alkynylation of tetrahydro-ß-carboline-1-carboxylic acid under peroxide-free condition is reported. The reaction is highly selective for the 1-position over the 3-position of tetrahydro-ß-carboline. The reaction can afford alkynylated or enaminone products depending on the reagent. The reaction proceeds through sequential decarboxylative iminium ion formation followed by an alkynylation and oxidative rearrangement cascade.

5.
Pediatr Nephrol ; 38(4): 1241-1248, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-35925426

RESUMO

BACKGROUND: Despite its utility, uncertainty exists on the feasibility of acute peritoneal dialysis (PD) and optimal PD catheter type for very low birth weight (VLBW < 1500 g) and extremely low birth weight (ELBW < 1000 g) infants. We hereby report our experience of acute PD among these high-risk infants and compare the outcome between stylet-based rigid catheter (SRC) and Cook Mac-Loc Multipurpose Drainage catheters® (CMMDC). METHODS: Case notes of infants < 1500 g undergoing PD between 2012 and 2021 in a network of five participating neonatal units supported by a tertiary paediatric nephrology centre in Kolkata, India, were retrospectively reviewed. PD was conducted either with SRC or after 2018 with CMMDC. Outcome parameters included complications, survival during PD, and survival to discharge. RESULTS: 24 infants (VLBW: n = 13 and ELBW: n = 11) underwent PD at median age 4.5 days (IQR 3-6) with either CMMDC (n = 14) or SRC (n = 10). Significant improvement in biochemical parameters and fluid removal was seen in both ELBW and VLBW infants. CMMDC was associated with significantly fewer PD-related complications 7/14 (50%) vs. 9/10 (90%) (p = 0.04) and higher survival during PD 13/14 (93%) vs. 5/10 (50%) (p = 0.02), without significant difference in survival to hospital discharge 8/14 (57%) vs. 3/10 (30%) (p = 0.25). CMMDC also enabled longer duration of PD, higher ultrafiltration, and better control of acidosis. Consumable cost was higher for CMMDC (USD$60) than SRC (USD$14). CONCLUSIONS: In a low resource setting, CMMDC had lower PD complications and superior short-term survival among ELBW/VLBW infants. A higher resolution version of the Graphical abstract is available as Supplementary information.


Assuntos
Diálise Peritoneal , Recém-Nascido , Criança , Lactente , Humanos , Estudos Retrospectivos , Diálise Peritoneal/efeitos adversos , Recém-Nascido de Peso Extremamente Baixo ao Nascer , Cateteres de Demora/efeitos adversos , Drenagem/efeitos adversos
6.
Nat Commun ; 13(1): 3965, 2022 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-35803924

RESUMO

Transition-metal dichalcogenides intercalated with 3d-transition metals within the van der Waals (vdW) gaps have been the focus of intense investigations owing to their fascinating structural and magnetic properties. At certain concentrations the intercalated atoms form ordered superstructures that exhibit ferromagnetic or anti-ferromagnetic ordering. Here we show that the self-intercalated compound Cr1+δTe2 with δ ≈ 0.3 exhibits a new, so far unseen, three-dimensionally ordered (2×2×2) superstructure. Furthermore, high resolution X-ray diffraction reveals that there is an asymmetric occupation of the two inequivalent vdW gaps in the unit cell. The structure thus lacks inversion symmetry, which, thereby, allows for chiral non-collinear magnetic nanostructures. Indeed, Néel-type skyrmions are directly observed using Lorentz transmission electron microscopy. The skyrmions are stable within the accessible temperature range (100-200 K) as well as in zero magnetic field. The diameter of the Néel skyrmions increases with lamella thickness and varies with applied magnetic field, indicating the role of long-range dipole fields. Our studies show that self-intercalation in vdW materials is a novel route to the formation of synthetic non-collinear spin textures.

7.
Am J Hum Biol ; 33(6): e23565, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-33417260

RESUMO

OBJECTIVES: To examine the pace of secular changes of selected body measurements and proportions of children and adolescents from Kolkata (India), between 1952-1966 and 1999-2011 in the context of differences between the sexes. METHODS: The study group consisted of 7753 children, adolescents and young adults (7-21 years of age) included in two series of studies (1952-1966 and 2005-2011). The measurements included: body height, sitting height, biacromial and biiliocristal diameters, as well as body mass. Additionally, subishial leg length was derived. The pace of the observed intergenerational trends was estimated on the basis of the differences of the mean values of the analyzed characteristics between both cohorts and expressed as the change of a given parameter for a decade. Information regarding the educational and professional status of the parents of participants was obtained using a questionnaire. RESULTS: In the majority of the analyzed characteristics, the pace of intergenerational changes was significantly higher among males, in comparison to females. It was visible especially during adolescence-between 11 and 19 years of age. The positive trends, especially, for characteristics such as body height or limb lengths occurred significantly quicker in males, in comparison to females. CONCLUSIONS: There were significant differences between the sexes in the pace of secular changes regarding the growth of the examined population. Considering the relatively homogenous economic situation of the families of the participants, it was more likely that those discrepancies effected from the social and domestic division of sexes, and the resulting differences in growth and development conditions.


Assuntos
Estatura , Adolescente , Criança , Feminino , Humanos , Índia , Masculino , Fatores Socioeconômicos , Adulto Jovem
8.
Anthropol Anz ; 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33475672

RESUMO

The purpose of this study was to assess the sexual dimorphism of body proportions and body composition among 16-19-year-olds from South Asia (India) and Central Europe (Poland). The study group consisted of the results of anthropometric measurements of 2008 youths (16-19-year-olds). 1098 of them came from Kolkata (India) and 910 from Kraków (Poland). For each of the analyzed anthropometric characteristics, the index of sexual dimorphism was calculated, basing on mean and standard deviation values. The body height was one of the most dimorphic features, in both populations. Also, the dimorphism in body adiposity, upper and lower limb, as well as trunk adiposity, pelvi-acromial and frame indicators was similar in both populations. Limbs-to-trunk adiposity index and trunk-to-total adiposity ratio were more dimorphic among the South Asian population, while the muscle mass was notably more dimorphic in the Polish adolescents. Such differences in the values of the Mollison's index may have been associated with the discrepancies in overall body fat ratio, which is much greater in the South Asians. Additionally, it may be related to different models of sexual preferences and attractiveness perception in both, culturally significantly varying, populations.

9.
J Biosoc Sci ; 53(1): 71-81, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32070439

RESUMO

The aim of this study was to investigate inter-generational changes in selected mid-upper-arm measurements of boys from Kolkata, India. The analysis was based on the anthropometric measurements of two cohorts of Bengali boys aged 7-16 from middle-class families, in 1982-83 and 2005-11. The two cohorts were compared in terms of their mid-upper-arm circumference (MUAC) and mid-upper-arm area (MUAA), mid-upper-arm muscle area (MUAMA), mid-upper-arm fat area (MUAFA) and Arm Fat Index (AFI). The significances of the differences were determined using two-way ANOVA. All features differed significantly between the examined cohorts and all showed a general positive secular trend. In most cases, the biggest differences were noted for 14- and 16-year olds and the smallest for the youngest boys. The contemporary boys seemed to have more favourable overall developmental conditions, probably related to socioeconomic progress in India over recent decades.


Assuntos
Adiposidade , Braço , Tamanho Corporal , Músculo Esquelético , Adolescente , Fatores Etários , Análise de Variância , Criança , Estudos de Coortes , Estudos Transversais , Humanos , Índia , Masculino
11.
Adv Mater ; 32(28): e2002043, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32484269

RESUMO

Skyrmions and antiskyrmions are magnetic nano-objects with distinct chiral, noncollinear spin textures that are found in various magnetic systems with crystal symmetries that give rise to specific Dzyaloshinskii-Moriya exchange vectors. These magnetic nano-objects are associated with closely related helical spin textures that can form in the same material. The skyrmion size and the period of the helix are generally considered as being determined, in large part, by the ratio of the magnitude of the Heisenberg to that of the Dzyaloshinskii-Moriya exchange interaction. In this work, it is shown by real-space magnetic imaging that the helix period λ and the size of the antiskyrmion daSk in the D2d compound Mn1.4 PtSn can be systematically tuned by more than an order of magnitude from ≈100 nm to more than 1.1 µm by varying the thickness of the lamella in which they are observed. The chiral spin texture is verified to be preserved even up to micrometer-thick layers. This extreme size tunability is shown to arise from long-range magnetodipolar interactions, which typically play a much less important role for B20 skyrmions. This tunability in size makes antiskyrmions very attractive for technological applications.

12.
Research (Wash D C) ; 2020: 4643507, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32318686

RESUMO

Highly conductive topological semimetals with exotic electronic structures offer fertile ground for the investigation of the electrical and thermal transport behavior of quasiparticles. Here, we find that the layer-structured Dirac semimetal PtSn4 exhibits a largely suppressed thermal conductivity under a magnetic field. At low temperatures, a dramatic decrease in the thermal conductivity of PtSn4 by more than two orders of magnitude is obtained at 9 T. Moreover, PtSn4 shows both strong longitudinal and transverse thermoelectric responses under a magnetic field. Large power factor and Nernst power factor of approximately 80-100 µW·cm-1·K-2 are obtained around 15 K in various magnetic fields. As a result, the thermoelectric figure of merit zT is strongly enhanced by more than 30 times, compared to that without a magnetic field. This work provides a paradigm for the decoupling of the electron and hole transport behavior of highly conductive topological semimetals and is helpful for developing topological semimetals for thermoelectric energy conversion.

13.
Nat Commun ; 11(1): 1115, 2020 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-32111842

RESUMO

Skyrmions and antiskyrmions are distinct topological chiral spin textures that have been observed in various material systems depending on the symmetry of the crystal structure. Here we show, using Lorentz transmission electron microscopy, that arrays of skyrmions can be stabilized in a tetragonal inverse Heusler with D2d symmetry whose Dzyaloshinskii-Moriya interaction (DMI) otherwise supports antiskyrmions. These skyrmions can be distinguished from those previously found in several B20 systems which have only one chirality and are circular in shape. We find Bloch-type elliptical skyrmions with opposite chiralities whose major axis is oriented along two specific crystal directions: [010] and [100]. These structures are metastable over a wide temperature range and we show that they are stabilized by long-range dipole-dipole interactions. The possibility of forming two distinct chiral spin textures with opposite topological charges of ±1 in one material makes the family of D2d materials exceptional.

14.
Nano Lett ; 20(1): 59-65, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31809059

RESUMO

Recently, magnetic antiskyrmions were discovered in Mn1.4Pt0.9Pd0.1Sn, an inverse tetragonal Heusler compound that is nominally a ferrimagnet, but which can only be formed with substantial Mn vacancies. The vacancies reduce considerably the compensation of the moments between the two expected antiferromagnetically coupled Mn sub-lattices so that the overall magnetization is very high and the compound is almost a "ferromagnet". Here, we report the observation of antiskyrmions in a second inverse tetragonal Heusler compound, Mn2Rh0.95Ir0.05Sn, which can be formed stoichiometrically without any Mn vacancies and which thus exhibits a much smaller magnetization. Individual and lattices of antiskyrmions can be stabilized over a wide range of temperature from near room temperature to 100 K, the base temperature of the Lorentz transmission electron microscope used to image them. In low magnetic fields helical spin textures are found which evolve into antiskyrmion structures in the presence of small magnetic fields. A weaker Dzyaloshinskii-Moriya interaction (DMI), that stabilizes the antiskyrmions, is expected for the 4d element Rh as compared to the 5d element Pt, so that the observation of antiskyrmions in Mn2Rh0.95Ir0.05Sn establishes the intrinsic stability of antiskyrmions in these Heusler compounds. Moreover, the finding of antiskyrmions with substantially lower magnetization promises, via chemical tuning, even zero moment antiskyrmions with important technological import.

15.
Am J Hum Biol ; 32(2): e23335, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31617273

RESUMO

OBJECTIVES: The aim of the study was to investigate the intergenerational changes of upper and lower limb lengths as well as the values of the upper, lower limb, and intermembral indicators of children, adolescents, and young adults from Kolkata (India) between 1952 to 1966 and 2005 to 2011. METHODS: The analysis was based on the results of anthropometric measurements of 7488 Bengali children, adolescents, and young adults. They were included in three cross-sectional surveys, carried out in 1955 to 1966, 1982 to 1983 (only males), and 2005 to 2011. The upper and lower limb lengths were obtained and the upper and lower limb indicators, as well as an intermembral index, were calculated. The differences between the cohorts were assessed using two-way ANOVA. RESULTS: Positive, statistically significant, secular trends regarding the length of the lower and upper limbs as well as the value of the lower limb index were observed. Negative intergenerational changes were noted for the values of the upper limb indicator and intermembral index, suggesting that the secular increase of the length of the upper limbs was less pronounced than those of the body height and lower limbs length. CONCLUSIONS: The secular increase regarding the lower limbs length was associated with the socioeconomic progress of the country, but the length of the upper limbs was less sensitive for those factors. It is also important to mention that there is still very little information on those characteristics in general, which further proves the need for similar studies.


Assuntos
Braço/anatomia & histologia , Perna (Membro)/anatomia & histologia , Adolescente , Estatura , Criança , Estudos Transversais , Feminino , Humanos , Índia , Masculino , Adulto Jovem
16.
Pediatr Obes ; 15(2): e12585, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31657149

RESUMO

BACKGROUND: India, as a developing country, is subjected to numerous socioeconomic changes. They can significantly influence human development and be mirrored by the secular trends regarding the adiposity and body fat distribution. OBJECTIVES: The aim of the study was to examine the intergenerational changes of adiposity and body fat distribution in Bengali boys, between 1982 and 2011. METHODS: The study group consisted of 2064 Bengali boys, aged 7-16, from the middle-class families, examined in two cross-sectional surveys in 1982-83 and 2005-2011. Triceps, biceps, subscapular and suprailiac skinfolds were measured. Their sum and the mean percentage of every skinfold were calculated. The percentage of body fat (%BF) was assessed using Slaughter's equations. RESULTS: Positive secular trend, significant for most of the age groups, was observed for %BF and sum of skinfolds. It was also present for suprailiac and subscapular skinfolds. CONCLUSIONS: Adiposity has significantly changed over the past three decades. The results confirm that the measurements of skinfold thickness are a great tool to relatively easily and accurately assess body adiposity in countries such as India. Moreover, further analysis of these trends can help to identify possible negative changes as well as establish their causes in a particular population.


Assuntos
Adiposidade , Distribuição da Gordura Corporal , Adolescente , Criança , Estudos Transversais , Humanos , Masculino , Dobras Cutâneas , Fatores de Tempo
17.
Nat Commun ; 10(1): 5305, 2019 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-31757968

RESUMO

Magnetic anti-skyrmions are one of several chiral spin textures that are of great current interest both for their topological characteristics and potential spintronic applications. Anti-skyrmions were recently observed in the inverse tetragonal Heusler material Mn1.4Pt0.9Pd0.1Sn. Here we show, using Lorentz transmission electron microscopy, that anti-skyrmions are found over a wide range of temperature and magnetic fields in wedged lamellae formed from single crystals of Mn1.4Pt0.9Pd0.1Sn for thicknesses ranging up to ~250 nm. The temperature-field stability window of the anti-skyrmions varies little with thickness. Using micromagnetic simulations we show that this intrinsic stability of anti-skyrmions can be accounted for by the symmetry of the crystal lattice which is imposed on that of the Dzyaloshinskii-Moriya exchange interaction. These distinctive behaviors of anti-skyrmions makes them particularly attractive for spintronic applications.

18.
Sci Adv ; 5(8): eaaw9867, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31453332

RESUMO

The band inversion in topological phase matters bring exotic physical properties such as the topologically protected surface states (TSS). They strongly influence the surface electronic structures of the materials and could serve as a good platform to gain insight into the surface reactions. Here we synthesized high-quality bulk single crystals of Co3Sn2S2 that naturally hosts the band structure of a topological semimetal. This guarantees the existence of robust TSS from the Co atoms. Co3Sn2S2 crystals expose their Kagome lattice that constructed by Co atoms and have high electrical conductivity. They serves as catalytic centers for oxygen evolution process (OER), making bonding and electron transfer more efficient due to the partially filled orbital. The bulk single crystal exhibits outstanding OER catalytic performance, although the surface area is much smaller than that of Co-based nanostructured catalysts. Our findings emphasize the importance of tailoring TSS for the rational design of high-activity electrocatalysts.

19.
Angew Chem Int Ed Engl ; 58(37): 13107-13112, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31342613

RESUMO

Conductivity, carrier mobility, and a suitable Gibbs free energy are important criteria that determine the performance of catalysts for a hydrogen evolution reaction (HER). However, it is a challenge to combine these factors into a single compound. Herein, we discover a superior electrocatalyst for a HER in the recently identified Dirac nodal arc semimetal PtSn4 . The determined turnover frequency (TOF) for each active site of PtSn4 is 1.54 H2 s-1 at 100 mV. This sets a benchmark for HER catalysis on Pt-based noble metals and earth-abundant metal catalysts. We make use of the robust surface states of PtSn4 as their electrons can be transferred to the adsorbed hydrogen atoms in the catalytic process more efficiently. In addition, PtSn4 displays excellent chemical and electrochemical stabilities after long-term exposure in air and long-time HER stability tests.

20.
J Biosoc Sci ; 51(4): 622-623, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30944053

RESUMO

The ethnicity of the studied group is one of the key characteristics that should be taken into consideration when analysing the problem of overweight and obesity. It is especially crucial in populations of countries such as India, where the proportion of the fat to lean mass and general adiposity are significantly different from those observed among Europeans. This can cause a higher risk of various metabolic-related diseases to appear at relatively lower absolute adiposity. Therefore, there is a need for further research regarding the issues of body mass and composition in Indian populations, to obtain additional information as well as to develop ethnically specific cut-off points.


Assuntos
Adiposidade , Etnicidade , Composição Corporal , Índice de Massa Corporal , Humanos , Índia , Obesidade
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