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1.
Angew Chem Int Ed Engl ; 63(11): e202401234, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38252519

RESUMO

Flexible thermoelectric devices of nanomaterials have shown a great potential for applications in wearable to remotely located electronics with desired shapes and geometries. Continuous powering up the low power flexible electronics is a major challenge. We are reporting a flexible thermoelectric module prepared from silver telluride (Ag2 Te) nanowires (NWs), which are chemically transformed from uniquely synthesized and scalable tellurium (Te) NWs. Conducting Ag2 Te NWs composites have shown an ultralow total thermal conductivity ~0.22 W/mK surpassing the bulk melt-grown Ag2 Te ~1.23 W/mK at ~300 K, which is attributed to the nanostructuring of the material. Flexible thermoelectric device consisting of 4 legs (n-type) of Ag2 Te NWs on polyvinylidene fluoride membrane displays a significant output voltage (Voc ) ~2.3 mV upon human touch and Voc ~18 mV at temperature gradient, ΔT ~50 K, which shows the importance of NWs based flexible thermoelectric devices to power up the low power wearable electronics.

2.
J Pediatr Ophthalmol Strabismus ; 61(2): 90-97, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37489626

RESUMO

PURPOSE: To assess pediatric ophthalmology-related information on TikTok (ByteDance). METHODS: The 12 most commonly searched terms from the American Association for Pediatric Ophthalmology and Strabismus website were queried as TikTok hashtags. The top 20 videos for each hashtag were analyzed for views, likes, comments, saves, shares, author status and gender, content, and engagement level ratio (ELR). Subanalysis of the educational videos for quality, understandability and actionability, and medical accuracy using the modified DISCERN (mDISCERN), Patient Education Materials Assessment Tool (PEMAT), and modified Medical Information and Content Index (mMICI) was performed. RESULTS: Analysis of 222 videos revealed a cumulative 191,337,973 views. Patients/families created the most videos (60.4%), followed by optometrists (14.4%), other (laypeople/unknown) (9.0%), ophthalmologists (7.7%), non-ophthalmology physicians (4.5%), and nurses (4.1%). Content was predominantly patient experience (56.8%), followed by educational (25.2%), humor (11.7%), self-promotional (3.6%), procedures (0.9%), other (0.9%), advertisements (0.5%), and career (0.5%). Educational videos had a lower ELR than humorous (3.3 vs 8.2, P < .001) and patient experience (3.3 vs 5.3, P < .001) videos, but more saves than patient experience videos (74 vs 25, P = .009). The mDISCERN scores were greater for videos authored by ophthalmologists (3, P < .001) and optometrists (2.5, P < .001) compared to lay-people (1.5). Ophthalmologist PEMAT understandability scores were greater than non-ophthalmology providers' (95.5% vs 67.4%, P = .002). There was no difference in PEMAT actionability (P = .743) or mMICI scores among the author subgroups (P = .206). CONCLUSIONS: Pediatric ophthalmology content on Tik-Tok ranges in quality and understandability. Additional research is needed to help promote posts created by eyecare providers to ensure evidence-based medical content reaches pediatric patients and their families. [J Pediatr Ophthalmol Strabismus. 2024;61(2):90-97.].


Assuntos
Oftalmologistas , Oftalmologia , Mídias Sociais , Estrabismo , Humanos , Criança
3.
J Recept Signal Transduct Res ; 43(1): 1-8, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36651469

RESUMO

THE PURPOSE OF THE ARTICLE: To identify novel small molecule antagonists of Urotensin II receptor with acceptable pharmacological profile. MATERIALS AND METHODS: Structure-activity-relationship (SAR) studies on 2-{N-[(2,4,5-trichlorophenoxy) acetyl]-N-methylamino}-3-pyrrolidinepropanamide series were conducted and shortlisted compounds were synthesized and evaluated in in vitro cell-based assays. Human and mouse Urotensin II receptor overexpressing CHO cells were used for calcium release and radioligand binding assays. Initial molecules in this series had solubility and inter-species variability issue in the calcium release assay. We, therefore, conducted SAR to overcome these 2 issues and molecules with accepted in vitro profile were evaluated further in mouse pressor response model to generate the in vivo proof of concept for UII receptor antagonization. RESULTS AND CONCLUSIONS: We report herewith identification of 2-{N-[(2,4,5-trichlorophenoxy)acetyl]-N-methylamino}-3-pyrrolidinepropanamides series to obtain novel small molecule antagonists of Urotensin II receptor with acceptable pharmacological profile.


Assuntos
Cálcio , Urotensinas , Camundongos , Cricetinae , Animais , Humanos , Cricetulus , Cálcio/metabolismo , Urotensinas/química , Urotensinas/metabolismo , Urotensinas/farmacologia , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Células CHO
4.
Ophthalmic Genet ; 44(6): 568-571, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36537327

RESUMO

BACKGROUND: Mutations in the DYNC1H1 gene have been linked to multiple neurologic syndromes with a multitude of clinical manifestations, both ocular and non-ocular. Previous case reports have outlined various ocular phenotypes, including cataracts of congenital onset, infantile onset, and adult onset with lack of further ophthalmologic detail. CASE PRESENTATION: Our case report outlines, in more detail, a 24-month-old male with a heterozygous mutation in the DYNC1H1 gene who developed a white, intumescent cataract in his left eye and a posterior subcapsular cataract in his right eye with evidence of progressive axial myopia. CONCLUSIONS: Based on the findings outlined in our case we suggest eye exams at regular intervals during early childhood in patients with DYNC1H1 mutations to screen for amblyogenic ocular pathology and potential rapidly developing cataracts.


Assuntos
Catarata , Miopia Degenerativa , Pré-Escolar , Adulto , Humanos , Masculino , Olho , Face , Catarata/genética , Mutação , Dineínas do Citoplasma
5.
Can J Ophthalmol ; 58(6): 565-569, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-36372135

RESUMO

OBJECTIVE: To quantify changes in ductions following nasal transposition of the split lateral rectus muscle (NTSLR) for treating third nerve palsy. DESIGN: Retrospective cohort study. PARTICIPANTS: A single eye from each patient with third nerve palsy treated with NTSLR with ocular motility measurements. METHODS: Observation of changes in pre- and postoperative ductions. Outcome measures including patient demographic and surgical factors associated with the ability to adduct beyond the midline after NTSLR were evaluated using multivariable logistic regression. RESULTS: A total of 116 patients met the inclusion criteria for this study. The NTSLR significantly decreased abduction (median of 0 limitation [interquartile range (IQR), 0-0] prior to surgery to -4 [IQR, -4 to -3] after NTSLR; p < 0.001), with a corresponding improvement in adduction (median, -5 [IQR, -5 to -4] prior to surgery to -4 [IQR, -4 to -3] after NTSLR; p < 0.001). There was no change in median supraduction or infraduction after NTSLR (p > 0.05). The ability to adduct beyond the midline after NTSLR was demonstrated in 42% of patients. Although not statistically significant, a trend toward a postoperative ability to adduct beyond the midline was seen in patients who had concurrent superior oblique muscle tenotomy (odds ratio [OR] = 5.08; 95% CI, 0.91-40.9) or who were designated with partial rather than complete third nerve palsy (OR = 2.29; 95% CI, 0.82-6.70). CONCLUSIONS: NTSLR improves the horizontal midline positioning of eyes with third nerve palsy. Most eyes lose the ability to abduct, but some regain a modest ability to adduct while vertical ductions remain unchanged.


Assuntos
Doenças do Nervo Oculomotor , Estrabismo , Humanos , Músculos Oculomotores/cirurgia , Estudos Retrospectivos , Movimentos Oculares , Nariz , Doenças do Nervo Oculomotor/diagnóstico , Doenças do Nervo Oculomotor/etiologia , Doenças do Nervo Oculomotor/cirurgia , Procedimentos Cirúrgicos Oftalmológicos , Estrabismo/cirurgia
6.
Front Pain Res (Lausanne) ; 3: 1032513, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36483945

RESUMO

Background: Retinopathy of prematurity (ROP) ophthalmologic examinations cause stress and pain. Infants' stress and pain can be measured non-invasively using skin conductance (SC) and high frequency heart rate variability (HF-HRV), reflecting sympathetic-mediated sweating and parasympathetic activity, respectively. Objectives: To test the utility of SC to detect sympathetic activation during ROP examination, and the contribution of HF-HRV to predict stability post-examination. Methods: In this prospective, single center study, we measured SC continuously pre-, during, and post-examination, and HRV at 24 h pre-ROP examination. Clinical data included stability [apneas, bradycardias, and desaturations (A/B/Ds)], and interventions post-examination. Results: SC increased 56% above baseline during ROP examination (p = 0.001) and remained elevated post-examination (p = 0.02). Post-hoc analysis showed higher illness acuity, represented by need for respiratory support, was associated with lower HF-HRV at 24 h pre-ROP examination (p = 0.001). Linear regression indicated lower HF-HRV at 24 h pre-examination contributed to the need for higher intervention (i.e., stimulation to breathe, oxygen support) particularly among infants with higher illness acuity [F(1, 15) = 5.05, p = 0.04; ß = -1.33, p = 0.04]. Conclusion: ROP examination induced a 2-fold increase in sympathetic activation which remained above baseline in recovery. Also, we propose that the low parasympathetic tone associated with autonomic imbalance contributes to instability and need for higher intervention to assure stabilization with A/B/D events. Our findings provide insight into the underestimation of adverse events associated with ROP examination and identification of infants who may be more vulnerable to potential sequelae following ROP examinations.

7.
Nat Commun ; 13(1): 5053, 2022 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-36030224

RESUMO

As the periodic atomic arrangement of a crystal is made to a disorder or glassy-amorphous system by destroying the long-range order, lattice thermal conductivity, κL, decreases, and its fundamental characteristics changes. The realization of ultralow and unusual glass-like κL in a crystalline material is challenging but crucial to many applications like thermoelectrics and thermal barrier coatings. Herein, we demonstrate an ultralow (~0.20 W/m·K at room temperature) and glass-like temperature dependence (2-400 K) of κL in a single crystal of layered halide perovskite, Cs3Bi2I6Cl3. Acoustic phonons with low cut-off frequency (20 cm-1) are responsible for the low sound velocity in Cs3Bi2I6Cl3 and make the structure elastically soft. While a strong anharmonicity originates from the low energy and localized rattling-like vibration of Cs atoms, synchrotron X-ray pair-distribution function evidence a local structural distortion in the Bi-halide octahedra and Cl vacancy. The hierarchical chemical bonding and soft vibrations from selective sublattice leading to low κL is intriguing from lattice dynamical perspective as well as have potential applications.

8.
Angew Chem Int Ed Engl ; 61(41): e202210783, 2022 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-35971950

RESUMO

Intrinsically low lattice thermal conductivity (κlat ) while maintaining the high carrier mobility (µ) is of the utmost importance for thermoelectrics. Topological insulators (TI) can possess high µ due to the metallic surface states. TIs with heavy constituents and layered structure can give rise to high anharmonicity and are expected to show low κlat . Here, we demonstrate that Bi1.1 Sb0.9 Te2 S (BSTS), which is a 3D bulk TI, exhibits ultra-low κlat of 0.46 Wm-1 K-1 along with high µ of ≈401 cm2  V-1 s-1 . Sound velocity measurements and theoretical calculations suggest that chemical bonding hierarchy and high anharmonicity play a crucial role behind such ultra-low κlat . BSTS possesses low energy optical phonons which strongly couple with the heat carrying acoustic phonons leading to ultra-low κlat . Further, Cl has been doped at the S site of BSTS which increases the electron concentration and reduces the κlat resulting in a promising n-type thermoelectric figure of merit (zT) of ≈0.6 at 573 K.

9.
RSC Adv ; 12(23): 14740-14756, 2022 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-35702231

RESUMO

1,5-Benzodiazepine is considered as one of the central moieties in the core unit of most drug molecules. Construction of such moieties with a new C-N bond under solvent-free and mild reaction conditions is challenging. Herein, we present a benign protocol for one pot synthesis of 1,5-benzodiazepine derivatives by using ferrocene (FC) supported activated carbon (AC) as a heterogeneous catalyst. The catalyst FC/AC was characterized by several analytical and spectroscopic techniques to reveal its physicochemical properties and for structural confirmation. The synthesized catalyst FC/AC was explored for its catalytic activity in the synthesis of 1,5-benzodiazepines through condensation of o-phenylenediamine (OPDA) and ketones (aromatic and aliphatic) under solvent-free conditions. The robust 10 wt% FC/AC catalyst demonstrated appreciable activity with 99% conversion of diamines and 91% selectivity towards the synthesis of the desired benzodiazepine derivatives under solvent-free conditions at 90 °C in 8 h. Additionally, several reaction parameters such as catalyst loading, reaction temperature, effect of reaction time and effect of different solvents on selectivity were also studied and discussed in-depth. To understand the scope of the reaction, several symmetrical and unsymmetrical ketones along with different substituted diamines were tested with the synthesized catalyst. All prepared reaction products were obtained in good to efficient yields and were isolated and identified as 1,5-benzodiazepines and no side products were observed. The obtained catalyst characterization data and the activity studies suggested that, the synergetic effect occurred due to the uniform dispersion of ferrocene over the AC surface with numerous acidic sites which triggered the reaction of diamine and ketone to form the corresponding benzodiazepine derivative and the same was illustrated in the plausible mechanism. Furthermore, the synthesized catalyst was tested for leaching and recyclability, and the results confirmed that catalyst can be used for up to six consecutive cycles without much loss in the catalytic activity and its morphology which makes the process sustainable and economical for scale-up production. The present method offered several advantages such as an ecofriendly method, excellent yields, sustainable catalytic transformation, easy work-up and isolation of products, and quick recovery of catalyst.

10.
J AAPOS ; 26(3): 141-142, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35469977

RESUMO

We introduce a portable retinoscopy device designed to allow simultaneous views of the retinoscope's reflex. With built-in Wi-Fi, it allows for viewing from any phone, tablet, or computer. The device easily attaches to a Welch Allyn retinoscope and could facilitate the teaching of retinoscopy for students, ophthalmic technicians, residents, and physicians.


Assuntos
Retinoscopia , Humanos
11.
Angew Chem Int Ed Engl ; 61(15): e202200071, 2022 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-35137508

RESUMO

Understanding the correlations of both the local and global structures with lattice dynamics is critical for achieving low lattice thermal conductivity (κlat ) in crystalline materials. Herein, we demonstrate local cationic off-centring within the global rock-salt structure of AgSbSe2 by using synchrotron X-ray pair distribution function analysis and unravel the origin of its ultralow κlat ≈0.4 W mK-1 at 300 K. The cations are locally off-centered along the crystallographic ⟨ 100 ⟩ direction by about ≈0.2 Å, which averages out as the rock-salt structure on the global scale. Phonon dispersion obtained by density functional theory (DFT) shows weak instabilities that cause local off-centering distortions within an anharmonic double-well potential. The local structural distortion arises from the stereochemically active 5s2 lone pairs of Sb. Our findings open an avenue for understanding how the local structure influences the phonon transport and facilitates the design of next-generation crystalline materials with tailored thermal properties.

13.
Science ; 371(6530): 722-727, 2021 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-33574210

RESUMO

High thermoelectric performance is generally achieved through either electronic structure modulations or phonon scattering enhancements, which often counteract each other. A leap in performance requires innovative strategies that simultaneously optimize electronic and phonon transports. We demonstrate high thermoelectric performance with a near room-temperature figure of merit, ZT ~ 1.5, and a maximum ZT ~ 2.6 at 573 kelvin, by optimizing atomic disorder in cadmium-doped polycrystalline silver antimony telluride (AgSbTe2). Cadmium doping in AgSbTe2 enhances cationic ordering, which simultaneously improves electronic properties by tuning disorder-induced localization of electronic states and reduces lattice thermal conductivity through spontaneous formation of nanoscale (~2 to 4 nanometers) superstructures and coupling of soft vibrations localized within ~1 nanometer around cadmium sites with local strain modulation. The strategy is applicable to most other thermoelectric materials that exhibit inherent atomic disorder.

14.
J AAPOS ; 24(6): 365.e1-365.e4, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33276095

RESUMO

BACKGROUND: The Pediatric Examination Assessment Rubric (PEAR) toolkit consists of an examination sheet and rubric designed to assess ophthalmology residents' performance on the pediatric eye examination. The purpose of this study was to evaluate the reliability of the PEAR toolkit. METHODS: Six ophthalmology residents (2 PGY-2, 4 PGY-3) at a single ACGME-accredited US program participated in 11 video-recorded pediatric ophthalmology patient encounters. Two pediatric ophthalmologists reviewed the videos and the residents' examination sheets to complete a PEAR evaluation. The inter-rater reliability of the rating for each of the 12 examination skills evaluated using PEAR was determined using kappa statistics, and reliability strength was categorized based on published guidelines (≤0, poor; 0-0.20, slight; 0.21-0.40, fair; 0.41-0.60, moderate; 0.41-0.60, substantial; 0.81-1.00, almost perfect). RESULTS: Eleven video encounters were completed. Of the 12 examination skills evaluated using PEAR, 9 had kappa scores with strengths of moderate to almost perfect reliability. Two examination skills, Worth 4-Dot and alignment, showed fair reliability. A kappa score could not be calculated for stereoacuity because of the lack of variability among the evaluators' raw scores. CONCLUSIONS: In our small sample of residents from a single institution, the PEAR toolkit showed inter-rater reliability.


Assuntos
Internato e Residência , Exame Físico , Criança , Competência Clínica , Humanos , Reprodutibilidade dos Testes
15.
J Am Chem Soc ; 142(36): 15595-15603, 2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32799442

RESUMO

Fundamental understanding of the correlation between chemical bonding and lattice dynamics in intrinsically low thermal conductive crystalline solids is important to thermoelectrics, thermal barrier coating, and more recently to photovoltaics. Two-dimensional (2D) layered halide perovskites have recently attracted widespread attention in optoelectronics and solar cells. Here, we discover intrinsically ultralow lattice thermal conductivity (κL) in the single crystal of all-inorganic layered Ruddlesden-Popper (RP) perovskite, Cs2PbI2Cl2, synthesized by the Bridgman method. We have measured the anisotropic κL value of the Cs2PbI2Cl2 single crystal and observed an ultralow κL value of ∼0.37-0.28 W/mK in the temperature range of 295-523 K when measured along the crystallographic c-axis. First-principles density functional theory (DFT) analysis of the phonon spectrum uncovers the presence of soft (frequency ∼18-55 cm-1) optical phonon modes that constitute relatively flat bands due to localized vibrations of Cs and I atoms. A further low energy optical mode exists at ∼12 cm-1 that originates from dynamic octahedral rotation around Pb caused by anharmonic vibration of Cl atoms induced by a 3s2 lone pair. We provide experimental evidence for such low energy optical phonon modes with low-temperature heat capacity and temperature-dependent Raman spectroscopic measurements. The strong anharmonic coupling of the low energy optical modes with acoustic modes causes damping of heat carrying acoustic phonons to ultrasoft frequency (maximum ∼37 cm-1). The combined effect of soft elastic layered structure, abundance of low energy optical phonons, and strong acoustic-optical phonon coupling results in an intrinsically ultralow κL value in the all-inorganic layered RP perovskite Cs2PbI2Cl2.

16.
Eur J Pharmacol ; 886: 173391, 2020 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-32745605

RESUMO

Urotensin II (U-II) has been found to be one of the most potent vasoconstrictor (Ames et al., 1999; Bohm et al., 2002) reported till date. U-II exerts its response via activation of a G-protein coupled receptor, Urotensin II receptor(UT). Binding of U-II to UT leads to an instant increase in the inositol phosphate turnover and intracellular Ca2+. Such an instant Ca2+ release and potent vasoconstriction exerted by U-II is expected to have an important role in the progression of cardiac diseases. We have previously shown that UT antagonist DS37001789 prevents U-II induced blood pressure elevation in mice (Nishi et al., 2019) in a dose dependent manner, with potent efficacy at 30 and 100 mg/kg. Further to this, we have also shown that DS37001789 ameliorates mortality in pressure-overload mice with heart failure (Nishi et al., 2020). We therefore conducted an extensive structure-activity relationship studies to identify molecules with superior efficacy. In the present manuscript, we report the identification of two potent, non-peptide small molecule antagonists of Urotensin II receptor (UT), RCI-0879 and RCI-0298 which blocked the action of U-II, both in vitro and in vivo. These molecules were found to be very potent in in vitro Ca2+ and radioligand binding assays using human and mouse UT over-expressing CHO cells. RCI-0879 and RCI-0298 also exhibited superior efficacy in in vivo mouse pressor response model using C57BL/6 mice, compared to our initial molecules (Nishi et al., 2019) and demonstrated ED50 values of 3.2 mg/kg and 6.8 mg/kg respectively. Our findings reported herewith, further strengthen our concept and belief in UT antagonization as a potential therapeutic approach for the management of chronic heart failure.


Assuntos
Anti-Hipertensivos/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Urotensinas/antagonistas & inibidores , Animais , Células CHO , Cálcio/metabolismo , Cricetinae , Cricetulus , Relação Dose-Resposta a Droga , Insuficiência Cardíaca/tratamento farmacológico , Humanos , Hipertensão/induzido quimicamente , Hipertensão/mortalidade , Camundongos , Camundongos Endogâmicos C57BL , Bibliotecas de Moléculas Pequenas , Relação Estrutura-Atividade
17.
Trials ; 21(1): 361, 2020 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-32345348

RESUMO

BACKGROUND: We reported that in our previous study that wearing intermittent occlusion therapy glasses (IO-therapy) for 4 hours (h) was non-inferior to patching for 2 h in 3 to 8-year-old children with amblyopia. We hypothesize that an intense regimen of 12-h IO-therapy per day for 4 weeks could be as effective as the standard regimen of 4-h IO-therapy per day for 12 weeks in treating moderate amblyopia in 3 to 8-year-old children. METHODS/DESIGN: A total of 56 children between 3 and 8 years of age with amblyopia in association with anisometropia and/or strabismus will be enrolled. All participants will be prescribed IO-therapy glasses (Amblyz™), set at 30-s opaque/transparent intervals (i.e., occluded 50% of wear time). They will be randomized to receive the standard regimen for 12 weeks or the intense regimen for 4 weeks. Adherence to using the IO-therapy glasses will be objectively monitored in each participant by means of a microsensor dose monitor. The primary study objective is to compare the effectiveness of an intense regimen to a standard regimen of IO-therapy in 3 to 8-year-old children with moderate amblyopia. The secondary study objectives are to determine whether adherence differs between an intense regimen and a standard regimen of IO-therapy, and to determine the dose-response relationship of IO-therapy. DISCUSSION: In addition to testing the effectiveness, this study will test for the first time the association between treatment adherence and the visual outcome of IO-therapy, which will enhance our understanding of the dose-response relationship of IO-therapy. If an intense regimen is shown to be effective, it would alter amblyopia treatment strategies and improve visual outcomes. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02767856. Registered on 10 May 2016.


Assuntos
Ambliopia/terapia , Cristais Líquidos , Privação Sensorial , Criança , Humanos , Monitorização Fisiológica , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento , Acuidade Visual
18.
J Am Chem Soc ; 141(51): 20293-20299, 2019 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-31804809

RESUMO

Understanding the mechanism that correlates phonon transport with chemical bonding and solid-state structure is the key to envisage and develop materials with ultralow thermal conductivity, which are essential for efficient thermoelectrics and thermal barrier coatings. We synthesized thallium selenide (TlSe), which is comprised of intertwined stiff and weakly bonded substructures and exhibits intrinsically ultralow lattice thermal conductivity (κL) of 0.62-0.4 W/mK in the range 295-525 K. Ultralow κL of TlSe is a result of its low energy optical phonon modes which strongly interact with the heat carrying acoustic phonons. Low energy optical phonons of TlSe are associated with the intrinsic rattler-like vibration of Tl+ cations in the cage constructed by the chains of (TlSe2)nn-, as evident in low temperature heat capacity, terahertz time-domain spectroscopy, and temperature dependent Raman spectroscopy. Density functional theoretical analysis reveals the bonding hierarchy in TlSe which involves ionic interaction in Tl+-Se while Tl3+-Se bonds are covalent, which causes significant lattice anharmonicity and intrinsic rattler-like low energy vibrations of Tl+, resulting in ultralow κL.

19.
JAMA ; 322(18): 1767-1768, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31714990
20.
J Educ Health Promot ; 8: 153, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31544118

RESUMO

INTRODUCTION: Association of ABO blood type with body mass index (BMI) was explored in the past studies, but literature on association of novel obesity markerssuch as total body fat and lean body mass (LBM) is scarce. The present study aimed to evaluate the relationship of ABO blood types with novel obesity markers in normal adolescents. MATERIALS AND METHODS: A cross-sectional study was done on 387 medical students. Bio-impedance analysis (BIA)-derived novel obesity markers such as body fat percent (BFP) and lean body mass (LBM) were recorded. Blood typing was done using slide-agglutination method. Mean and SD were calculated; analysis of variance and Chi-square (χ2) correlation were used to determine the relationship between ABO blood types and obesity markers. RESULTS: Highest propensity for BFP and LBM was seen in blood groups AB and B (25.09 ± 8.92 and 44.45 ± 6.91) respectively. Highly significant (P < 0.001) differences were observed in the values of BFP and LBM in normal and obese participants across ABO blood types. Prevalence of obesity did not show significant relationship (χ2 = 2.069; P = 0.913) with ABO blood types. CONCLUSIONS: Unlike BMI, novel obesity markers (BFP and LBM) significantly differ across ABO blood groups in normal and obese population. The findings suggest that ABO blood type might have role in determining body composition. This will be helpful in recognition of the participants at the risk of obesity on the basis of their blood groups.

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