Lewis Acid Site Assisted Bifunctional Activity of Tin Doped Gallium Oxide and Its Application in Rechargeable Zn-Air Batteries.

The enhanced safety, superior energy, and power density of rechargeable metal-air batteries make them ideal energy storage systems for application in energy grids and electric vehicles. However, the absence of a cost-effective and stable bifunctional catalyst that can replace expensive platinum (Pt)-based catalyst to promote oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) at the air cathode hinders their broader adaptation. Here, it is demonstrated that Tin (Sn) doped ß-gallium oxide (ß-Ga2 O3 ) in the bulk form can efficiently catalyze ORR and OER and, hence, be applied as the cathode in Zn-air batteries. The Sn-doped ß-Ga2 O3 sample with 15% Sn (Snx =0.15 -Ga2 O3 ) displayed exceptional catalytic activity for a bulk, non-noble metal-based catalyst. When used as a cathode, the excellent electrocatalytic bifunctional activity of Snx =0.15 -Ga2 O3 leads to a prototype Zn-air battery with a high-power density of 138 mW cm-2 and improved cycling stability compared to devices with benchmark Pt-based cathode. The combined experimental and theoretical exploration revealed that the Lewis acid sites in ß-Ga2 O3 aid in regulating the electron density distribution on the Sn-doped sites, optimize the adsorption energies of reaction intermediates, and facilitate the formation of critical reaction intermediate (O*), leading to enhanced electrocatalytic activity.

Probing the Origin of Ferro-/Antiferromagnetic Exchange Interactions in Cu(II)-4f Complexes.

The mechanistic investigations between Cu(II) and the anisotropic lanthanides (Ln(III)) are not much explored to date. This is due to the complicated energy spectrum which arises due to the orbital angular momentum of anisotropic lanthanides. Interestingly, the exchange coupling J in Ln(III)-Cu(II) systems was found to be antiferromagnetic for <4f7 metal ions and ferromagnetic for ≥4f7 metal ions, while the net magnitude of JTotal strength gradually decreases moving from f1 to f13. While this is established in several examples, the reason for this intriguing trend is not rationalized. In this article, we have taken up these challenging tasks by synthesizing a family of complexes with the general molecular formula [Cu2Ln(HL)4(NO3)](NO3)2, where Ln = La (1-La), Ce (2-Ce), Pr (3-Pr), Gd (4-Gd), Tb (5-Tb), Dy (6-Dy), and Ho (7-Ho) and HL = C15H15N1O3; (2-methoxy-6-[(E)-2'-hydroxymethyl-phenyliminomethyl]-phenolate) is a monodeprotonated tridentate Schiff base ligand. Detailed dc magnetic susceptibility measurements performed for all the complexes reveal that the Cu(II) ion is coupled ferromagnetically to the respective Ln(III) ion, which has more than seven electrons in the 4f shell, while an antiferromagnetic coupling is witnessed if Ln(III) has less than seven electrons. The strength of the exchange coupling constant was quantitatively determined for representative complexes from the high-field/high-frequency electron paramagnetic resonance spectroscopy which follows the order of 4-Gd (1.50(10) cm-1) > 5-Tb (1.18(10) cm-1) > 6-Dy (0.56(10) cm-1 based on the -2JCu-Ln(SCu1→·JLnz→+SCu2→·JLnz→) spin Hamiltonian. The increased axiality in 5-Tb and 6-Dy due to the presence of 3d ions in the near vicinity of an oblate ion and the increased exchange coupling strength between Cu(II) and Tb(III) or Dy(III) is the ideal combination to stabilize magnetic bistability in these complexes in the absence of an external magnetic field with the effective energy barrier of 15.7 K (τo = 2.49 × 10-6 s) and 12.6 K (τo = 1.70 × 10-5 s), respectively. To rationalize this experimental trend, we have performed ab initio CASSCF and DFT calculations. To compute the J values, we have employed POLY_ANISO routines and utilized the computed data to establish the generic mechanism of magnetic coupling in {Cu-Ln-Cu} motifs. These mechanistic findings reveal the importance of 5d orbitals and their energy with respect to the dx2-y2 orbital of Cu(II) ions in controlling the magnetic coupling of {Cu-4f} complexes.

Role of Coordination Geometry on the Magnetic Relaxation Dynamics of Isomeric Five-Coordinate Low-Spin Co(II) Complexes.

To investigate the influence of the coordination geometry on the magnetization relaxation dynamics, two geometric isomers of a five-coordinate low-spin Co(II) complex with the general molecular formula [Co(DPPE)2Cl]SnCl3 (DPPE = diphenylphosphinoethane) were synthesized and structurally characterized. While one isomer has a square pyramidal geometry (Co-SP (1)), the other isomer figures a trigonal bipyramidal geometry (Co-TBP (2)). Both complexes were already reported elsewhere. The spin state of these complexes is unambiguously determined by detailed direct current (dc) magnetic data, X-band, and high-frequency EPR measurements. Slow relaxation of magnetization is commonly observed for systems with S > 1/2. However, both 1 and 2 show field-induced slow relaxation of magnetization. Especially 1 shows relaxation times up to τ = 35 ms at T = 1.8 K, which is much longer than the reported values for undiluted Co(II) low-spin monomers. In 2, the maximal field-induced relaxation time is suppressed to τ = 5 ms. We attribute this to the change in g-anisotropy, which is, in turn, correlated to the spatial arrangement of ligands (i.e., coordination geometry) around the Co(II) ions. Besides the detailed electronic structure of these complexes, the experimental observations are further corroborated by theoretical calculations.

Breastfeeding rates at discharge for very low birthweight neonates and their determinants: An observational study from a tertiary care neonatal intensive care unit in India.

BACKGROUND: Mother's milk is the best milk for neonates. Preterm very low birthweight (VLBW) neonates face many challenges leading to low rates of breastfeeding at discharge. AIMS: (i) To determine the proportion of <32 weeks preterm VLBW neonates who are exclusively breastfed (EB) at discharge and (ii) determinants of exclusive breastfeeding (EBF) at discharge. METHODS: An observational study was conducted for a duration of 1 year, from May 2019 to April 2020 in a tertiary care neonatal intensive care unit (NICU) in North India. Consecutive <32 weeks preterm VLBW neonates admitted within 72 h of birth and on full enteral feeds (FEF) within 10 days of birth were included in this study and followed up till discharge. RESULTS: Forty-four of 97 (45.4%) preterm VLBW neonates were exclusively breastfed and 31/97 (32%) received more than 80% mother's own milk (MOM) at discharge. Male sex (P = 0.03), those whose first feed had any amount of MOM (P = 0.038) or exclusive MOM in their first feed or when initiated on first FEF (P = 0.002), and neonates with longer duration of hospital stay (P = 0.035) had an increased chance of being exclusively breastfed at discharge. CONCLUSION: Preterm VLBW neonates who receive any amount of MOM in their first feed or first FEF, male infants and those who stay longer in hospital are more likely to be exclusively breastfed at discharge.

Benzimidazole-based fluorophores for the detection of amyloid fibrils with higher sensitivity than Thioflavin-T.

Protein aggregation into amyloid fibrils is a key feature of a multitude of neurodegenerative diseases such as Alzheimer's, Parkinson's, and Prion disease. To detect amyloid fibrils, fluorophores with high sensitivity and better efficiency coupled with the low toxicity are in high demand even to date. In this pursuit, we have unveiled two benzimidazole-based fluorescence sensors ([C15 H15 N3 ] (C1) and [C16 H16 N3 O2 ] (C2), which possess exceptional affinity toward different amyloid fibrils in its submicromolar concentration (8 × 10-9  M), whereas under a similar concentration, the gold standard Thioflavin-T (ThT) fails to bind with amyloid fibrils. These fluorescent markers bind to α-Syn amyloid fibrils as well as amyloid fibrils forming other proteins/peptides including Aß42 amyloid fibrils. The 1 H-15 N heteronuclear quantum correlation spectroscopy nuclear magnetic resonance data collected on wild-type α-Syn monomer with and without the fluorophores (C1 and C2) reveal that there is weak or no interactions between C1 or C2 with residues in α-Syn monomer, which indirectly reflects the specific binding ability of C1 and C2 to the α-Syn amyloid fibrils. Detailed studies further suggest that C1 and C2 can detect/bind with the α-Syn amyloid fibril as low as 100 × 10-9  M. Extremely low or no cytotoxicity is observed for C1 and C2 and they do not interfere with α-Syn fibrillation kinetics, unlike ThT. Both C1/C2 not only shows selective binding with amyloid fibrils forming various proteins/peptides but also displays excellent affinity and selectivity toward α-Syn amyloid aggregates in SH-SY5Y cells and Aß42 amyloid plaques in animal brain tissues. Overall, our data show that the developed dyes could be used for the detection of amyloid fibrils including α-Syn and Aß42 amyloids with higher sensitivity as compared to currently used ThT.

Vitamin D Status of Very Low Birth Weight Neonates at Baseline and Follow-up after Daily Intake of 800 IU Vitamin D.

INTRODUCTION: Vitamin D deficiency (VDD) is rampant in neonates. Recommendations for supplementation are variable. METHODS: An observational study was done on less than 32 weeks of very low birth weight neonates to find prevalence of VDD (<20 ng/ml) at baseline; at 38 ± 2 weeks post-menstrual age (PMA) after daily intake of 800 IU vitamin D (vit D). Secondary objectives were to find determinants of VDD, to compare growth in deficient; vit D sufficient (VDS) neonates; to find vit D toxicity. RESULTS: Of 83 neonates, 81 (97.6%) were VDD at baseline and 5 (6%) at 38 ± 2 weeks PMA. Determinants for VDD at baseline were inadequate maternal sun exposure (p < 0.001) and vit D supplementation (p = 0.007). Factors for VDD at 38 ± 2 weeks PMA were male gender (p = 0.049), morbidities (p = 0.006), ventilation >24 h (<0.001), sepsis (p = 0.032), caffeine (p ≤ 0.001) and missed supplements (p < 0.001). Weight and length gain of VDD to VDS neonates were (6.70 ± 2.40 to 8.96 ± 2.21 g/day); (0.82 ± 0.34 to 1.08 ± 0.37 cm/week), respectively (p < 0.001). Head circumference gain (cm/week) of VDS; VDD neonates was 0.58 ± 0.09; 0.54 ± 0.06 (p = 0.054), respectively. No neonates developed vit D toxicity. CONCLUSIONS: In preterm VLBW neonates, the prevalence of VDD was 97.6% but decreased by >90% at 38 ± 2 weeks with a daily intake of 800 IU vit D. Inadequate maternal vit D intake and sun exposure determined low baseline vit D status of neonates. Male gender, morbidities, ventilation, sepsis, caffeine, missed vitamin D supplements were determinants of poor vit D status at follow-up. Weight gain and length increments were more in the VDS group.

Curcumin loaded poly (amidoamine) dendrimer-plamitic acid core-shell nanoparticles as anti-stress therapeutics.

Despite poor bioavailability of the drug and in vivo stability, curcumin has been reported for many pharmacological activities. Considering the potential of dendrimers as a drug delivery system, current research work is focused on the formulation and characterization of G4 PAMAM dendrimer-Palmitic acid core-shell nanoparticle-containing curcumin as antistress therapeutics to maximize the bioavailability of curcumin. Various formulations were prepared using different concentrations of palmitic acid and an optimized ratio of dendrimer and curcumin. All formulations were investigated for evaluation of physicochemical parameters, encapsulation efficiency, and in vitro release. Particle size, PDI, zeta-potential, and encapsulation efficiency of final formulation was found to be 257.9 ± 0.365 nm, 0.10 ± 0.004, 3.59 ± 0.167 mV, and 80.87%, respectively. In vitro release studies have shown that 53.62 ± 2.431% of the drug was released after 24 h. In vivo studies pharmacokinetic parameters, drug distribution, pharmacological, and toxicological were also estimated using swiss albino mice. The findings have shown the selected formulation is better than plain curcumin formulation.

Facile Synthesis of Concave Cuboid Au NCs with Precisely Tunable Dimensions and Mechanistic Insight.

Concave cuboid (CCB) nanostructure is a member of the high-index facet (HIF) nanocrystals (NCs) family, geometrically derived from regular cuboid-excavation of each face. CCB NCs hold some additional characteristics such as surface cavity and sharp edges and corners as compared to its convex counterpart that makes it relatively more active in applications like electrochemical catalysis, surface enhanced Raman spectroscopy (SERS), and plasmonics. To date, there are only few reports available on the synthesis of CCB Au NCs where Br- containing surfactants have been used as a shape directing and stabilizing agent. However, none of them led to decent yield and size tunability. Herein, we report a robust seed mediated growth strategy where cetyltrimethylammonium chloride (CTAC) and tannic acid (TA) have been used as shape-directing/stabilizing and mild reducing agents, respectively. Our method not only allows the high yield fabrication of CCB Au NCs with uniform shape and size but also precise control over dimensions and degree of surface concavity. Moreover, the investigation of growth mechanism revealed that the evolution of CCB Au NCs from cylindrical nanorods (NRs) take place via arrow-headed nanorods and truncated CCB nanostructures. Furthermore, it has been observed that the presence of excess of Cl- is indeed playing a decisive role despite the headgroup of counter cationic part of surfactant. We anticipate that our findings may pave the path to design new synthetic strategies and understand the evolution of new nanostructures.

Influence of a Counteranion on the Zero-Field Splitting of Tetrahedral Cobalt(II) Thiourea Complexes.

Four mononuclear cobalt(II) complexes with pseudo tetrahedral geometry were isolated with different counteranions; their structure solution reveals the molecular formula as [Co(L1)4]X2 [where L1 = thiourea (NH2CSNH2) and X = NO3 (1), Br (2), and I (3)] and [Co(L1)4](SiF6) (4). The detailed analysis of direct-current (dc) magnetic data reveals a zero-field splitting (ZFS; D) with mS = ±3/2 as the ground levels (D < 0) for the four complexes. The magnitude of the ZFS parameter is larger, in absolute value, for 1 (D = -61.7 cm-1) than the other three complexes (-5.4, -5.1, and -12.2 cm-1 for 2-4, respectively). The sign of D for 1, 2, and 4 was unambiguously determined by X-band electron paramagnetic resonance (EPR) spectroscopy of the diluted samples (10%) at 5 K. For 3, the sign of D was naturally endorsed from the frequency-dependent out-of-phase signal (χM″) observed in the absence of an external dc magnetic field and confirmed by high-frequency EPR (70-600 GHz) experiments performed on a representative pure polycrystalline 3, which gave a quantitative D value of -5.10(7) cm-1. Further, the drastic changes in the spin Hamiltonian parameters and their related relaxation dynamics phenomena (of 2-4 compared to 1) were rationalized using ab initio complete-active-space self-consistent field/n-electron valence perturbation theory calculations. Calculations disclose that the anion-induced structural distortion observed in 2-4 leads to a nonfavorable overlap between the π orbital of cobalt(II) and the π* orbital of the sulfur atom that reduces the overall |D| value in these complexes compared to 1. The present study demonstrates that not only the first but also the second coordination sphere significantly influences the magnitude of the ZFS parameters. Particularly, a reduction of D of up to ∼90% occurs (in 2-4 compared to 1) upon a simple variation of the counteranions and offers a viable approach to modulate ZFS in transition-metal-containing single-molecule magnets.

Substituted versus Naked Thiourea Ligand Containing Pseudotetrahedral Cobalt(II) Complexes: A Comparative Study on Its Magnetization Relaxation Dynamics Phenomenon.

A series of mononuclear tetrahedral cobalt(II) complexes with the general molecular formula [Co(L1)2X2] [where L1 = tetramethylthiourea ([(CH3)2N]2C═S) and X = Cl (1), Br (2), and I (3)] were isolated, and their structures were characterized by single-crystal X-ray diffraction. The experimental direct-current magnetic data are excellently reproduced by fitting both χM T( T) and M( H) simultaneously using the spin Hamiltonian (SH) parameters D1 = -18.1 cm-1 and g1,iso = 2.26, D2 = -16.4 cm-1 and g2,iso = 2.33, and D3 = -22 cm-1 and g3,iso = 2.4 for 1-3, respectively, and the sign of D was unambiguously confirmed from X-band electron paramagnetic resonance measurements. The effective energy barrier extracted for the magnetically diluted complexes 1-3 (10%) is larger than the barrier observed for the pure samples and implies a nonzero contribution of dipolar interaction to the magnetization relaxation dynamics. The SH parameters extracted for the three complexes drastically differ from their respective parent complexes that possess the general molecular formula [Co(L)2X2] [where L = thiourea [(NH2)2C═S] and X = Cl (1a), Br (2a), and I (3a)], which is rationalized by detailed ab initio calculations. An exhaustive theoretical study reveals that both the ground and excited states are not pure but rather multideterminental in nature (1-3). Noticeably, the substitution of L by L1 induces structural distortion in 1-3 on the level of the secondary coordination sphere compared to 1a-3a. This distortion leads to an overall reduction in | E/ D| of 1-3 compared to 1a-3a. This may be one of the reasons for the origin of the slower relaxation times of 1-3 compared to 1a-3a.

Predictors of Poor Outcome in Neonates with Pyogenic Meningitis in a Level-Three Neonatal Intensive Care Unit of Developing Country.

BACKGROUND: The mortality of neonatal pyogenic meningitis is reduced to 10-15%, but morbidity is unchanged. METHODS: Primary objective is to determine the outcome, i.e. death or abnormal neurological examination (NE) at discharge and abnormal developmental quotient (DQ) at 3 months. Secondary objective is to find predictors of poor outcome. RESULTS: In all, 89 neonates enrolled, 10 expired and 24 neonates had abnormal NE at discharge. A total of 59 neonates came for follow up, 13 had DQ < 70. Prolonged shock (odds ratio, OR: 8.28; p = 0.001), coma (OR: 4.3; p = 0.001), seizures (OR: 14; p = 0.012), mechanical ventilation (OR: 18.55; p = 0.00), orogastric feeding (OR: 2.78; p = 0.042) and electroencephalography (EEG; OR: 9.6; p = 0.00) predicted poor short-term outcome. Abnormal NE at discharge (OR: 15.6; p = 0.001), EEG (OR = 10.60; p = 0.00) and brainstem-evoked reflex audiometry (OR = 37.20, p = 0.00) predicted a low DQ at 3 months. Mortality and morbidity of neonates with Pyogenic Meningitis (PM) were similar to that in developed countries. Outcome depended on severity of the disease and NE at discharge.

Postexchange transfusion-related acute lung injury in a term neonate.

We report a successful case where a newborn with transfusion-related acute lung injury following an exchange transfusion was effectively treated using conservative methods, eliminating the need for surfactant therapy. Very few instances of this complication have been documented globally. A low birth weight, small for gestational age, term neonate, diagnosed with hyperbilirubinaemia due to Rh incompatibility, experienced sudden respiratory distress in the form of severe retractions, tachypnoea and cyanosis 3 hours after the procedure. Neonate required mechanical ventilation on the grounds of mixed acidosis and diffuse alveolar infiltrates on the chest radiograph. The medical team suspected and treated the baby for transfusion-related acute lung injury through conservative measures. Transfusion-related acute lung injury, an acute life-threatening complication of blood component transfusion, can exhibit symptoms in neonates that are frequently misinterpreted as sepsis. The baby was discharged in good health after successful management after 19 days.

Nonalcoholic Fatty Liver Disease (NAFLD) and Cardiovascular Risk: Is Imaging Helpful?

Nonalcoholic Fatty Liver Disease (NAFLD) is proving to be a globally prevalent condition. Moreover, NAFLD may be an independent risk factor associated with higher cardiovascular (CVD) morbidity and mortality. Further studies are needed to assess whether NAFLD needs to be included in the atherosclerotic risk score algorithms or whether patients with NAFLD need to be screened early on to assess their CVD risk especially since imaging such as positron emission tomography can be used to assess both NAFLD and CV disease at the same time. Therefore employing cardiovascular imaging modalities to investigate the incidence, extent, and nature of atherosclerotic lesions in NAFLD may be beneficial. Additionally, whether treating NAFLD halts the progression of CVD on imaging remains to be seen. Further research to delineate NAFLD and CVD associations, deciphering screening imaging modalities, and investigating targeted interventions could improve CVD morbidity and mortality in NAFLD.

Comparative Evaluation of Surgical Operability with and without Induction Chemotherapy in Locally Advanced Head and Neck Squamous Cell Carcinoma.

To compare and evaluation of surgical operability with and without induction chemotherapy in locally advanced head and neck squamous cell carcinoma. Head and neck malignancy grossly refers to squamous cell carcinomas of head and neck (HNSCC) have multiple treatment modalities and strategies, when opted in an appropriate manner renders tumours curable. The aim of this study is to compare and evaluation of surgical operability with and without induction chemotherapy in locally advanced head and neck squamous cell carcinoma. A prospective observational study involving 50 patients of histologically proven squamous cell carcinoma of head and neck region. Patients were categorized into two major groups, group-1 patients included resectable tumour stage and group-2 included unresectable tumour stage. Both groups were compared after appropriate chemotherapy and surgical intervention. There were a total of 78% males and 22% females with majority of patients in age group of 41-60 years. 54% patients had ulcerative type of growth pattern and most patients had primary site of lesion in oral cavity. 50% patients had moderately differentiated squamous cell carcinoma. Induction chemotherapy was considered in 70% of patients, while majority of patients were belonging to T4N2M0 stage. In this study, we recommend that the borderline category of patients who are initially in an unresectable tumour stage can undergo induction chemotherapy to downstage and shrink the tumour to a resectable stage following which the appropriate surgical intervention should be done with a close monitoring and sustained follow up to prevent recurrence.

Pyridoxine-Dependent Epilepsy With Poor Neurodevelopmental Outcome: Case Report.

Pyridoxine-dependent seizures are a rare cause of recurrent seizures in the neonatal period that are resistant to most of the antiepileptic medications, but respond to pyridoxine. There is a wide spectrum of clinical manifestations, and in the absence of biochemical markers, clinical diagnosis is often delayed. We report a case of neonatal seizures that initially responded to antiepileptic drugs but later presented with intractable seizures and metabolic abnormalities. Clinical exome sequencing was suggestive of ALDH7A1 mutation.

Arthrogryposis, renal dysfunction, cholestasis syndrome in a neonate: an uncommon association of common problems.

A male infant born out of non-consanguineous marriage to a primigravida presented to us as his third hospitalisation with ichthyotic lesions all over the body, cholestatic jaundice, multiple joint contractures and a history of recurrent sepsis. Blood and urine investigations revealed Fanconi syndrome, hypothyroidism and direct hyperbilirubinaemia with elevated liver enzymes and normal gamma glutamyl transpeptidase levels. The combination of arthrogryposis, renal dysfunction and cholestasis led to the suspicion of arthrogryposis, renal tubular dysfunction, cholestasis (ARC) syndrome, which was then proved by genetic testing. The baby was managed conservatively with respiratory support, antibiotics, multivitamins, levothyroxine and other supportive measures but succumbed to the illness on day 15 of hospitalisation. Genetic analysis using next-generation sequencing was confirmatory of a homozygous mutation in VIPAS39 gene leading to ARC syndrome type 2 in the present case. Genetic counselling was provided and prenatal testing was advised to the parents for future pregnancies.

Antioxidant and antiarthritic potential of berberine: In vitro and in vivo studies.

Objective: To extract and isolate berberine from Berberis aristata (Berberidaceae). Isolated berberine was characterised using spectroscopy and its antioxidant and antiarthritic activity was analyzed. Methods: The berberine was isolated from B. aristata using microwave-assisted extraction (MAE) and characterised by a spectroscopic technique. The isolated berberine was evaluated for its antioxidant activity in DPPH, nitric oxide, and superoxide scavenging assays, while antiarthritic activity was evaluated in the complete freund's adjuvant (CFA)-induced arthritis rat model. Results: The antioxidant activity of berberine revealed potent antioxidant activity in DPPH, nitric oxide, and superoxide scavenging assays. The in vivo antiarthritic activity of berberine in the CFA-induced arthritis rat model showed a significant reduction in paw diameter, arthritic score, and an increase in body weight. Furthermore, a concentration-dependent ameliorating action of berberine on haematological parameters was noticed. Proinflammatory biomarkers, including IL-6, IL-10, and TGF-b in serum were reported, and histopathology examination revealed that berberine decreased pannus formation, synovial hyperplasia, and bone erosion. Radiographic investigation showed soft tissue inflammation, bone resorption and erosion, joint gap reduction, and substantial connective tissue expansion after treatment with berberine. Conclusion: The ameliorating action on haematological parameters and proinflammatory biomarkers of berberine makes them a suitable remedy for the treatment of arthritis.

Congenital myopathy presenting as recurrent pneumonia with lung collapse and pulmonary artery hypertension.

A boy presented with cough, breathlessness for 1 month, fever for 1 week with similar previous episodes without hospitalisation. He had generalised muscle wasting, acute chronic malnutrition and required immediate ventilation. Provisional diagnosis of recurrent pneumonia with failure to thrive was made. As serial chest X-rays showed recurrent lung collapse, congenital lung anomalies were ruled out. 2D-echocardiography showed pulmonary arterial hypertension. Workup for congenital immunodeficiency and cystic fibrosis was negative. There was no improvement in muscle mass despite total parenteral nutrition. He was noticed to have myopathic facies. History was reviewed when the mother reported reduced fetal movements in this pregnancy. The patient had low voice amplitude. Creatine kinase levels were normal. Muscle biopsy followed by whole exome sequencing identified frameshift duplication NM_020451.3(SELENON):c.249_250dupGG (p.Asp84Glyfs*17), thus, confirming diagnosis of SEPN1-related congenital myopathy (CM) with fibre-type disproportion. Respiratory system involvement was distracter, emphasising consideration of CM while evaluating persistent lung collapse with muscle wasting.

Ultrafast time-resolved carrier dynamics in tellurium nanowires using optical pump terahertz probe spectroscopy.

We report carrier relaxation dynamics in semiconducting tellurium nanowires (average diameter ∼ 10 nm) using ultrafast time-resolved terahertz spectroscopy. After photoexcitation using an 800 nm pump pulse, we observed an initial increase in the THz conductivity due to the absorption of THz radiation by photoexcited carriers. The time evolution of the differential conductivity (Δσ(τpp) = σpump on(τpp) - σpump off) shows a bi-exponential relaxation with the initial fast decay time scale of τ1 ∼ 25 ps followed by a longer relaxation time constant of τ2 ∼ 100 ps. Interestingly, the two time scales depend on the amount of the capping agent present on the surface of TeNWs, showing a faster relaxation of the photoexcited carriers as the percentage of capping decreases. This is physically interpreted as the surface state mediated relaxation mechanism of the photo-pumped carriers depending on the density of available surface states. A quantitative understanding is obtained using a coupled rate equation model taking into account the decay mechanisms determined from the surface mediated relaxation rate (DS) and direct recombination rate (DR) of the electron-hole pairs. Furthermore, the measured lattice temperature (TL) dependent dynamics, showing a faster relaxation at lower temperature, is understood using the same rate equation model, giving a power law dependence of the electron-hole recombination rate (DR) on TL as DR ∝ TL-1/2. This is explained by estimating DR using the van Roosbroeck-Shockley theory taking into account the density of states () of one-dimensional nanowires. Furthermore, to understand the measured frequency-dependent THz photoconductivity, we model Δσ(ω) using the Boltzmann transport equation taking into account the energy-dependent scattering rates showing the dominant role of short range (Γsr) and Coulomb scattering (ΓC) rates in the relaxation process, which further provides a measure of the charged and neutral impurity concentrations.