Chronic thromboembolic pulmonary hypertension (CTEPH) is a specific type of pulmonary hypertension (PH) and the major component of Group 4 pulmonary hypertension (PH). It is caused by pulmonary ...vasculature obstruction that leads to a progressive increase in pulmonary vascular resistance and, ultimately, to failure of the right ventricle. Pulmonary thromboendarterectomy (PEA) is the only definitive therapy, so a timely diagnosis and early referral to a specialized PEA center to determine candidacy is prudent for a favorable outcome. Percutaneous balloon pulmonary angioplasty (BPA) has a potential role in patients unsuitable for PEA. Medical therapy with riociguat is the only PH-specific medical therapy currently approved for the treatment of inoperable or persistent CTEPH. This review article aims to revisit CTEPH succinctly with a review of prevailing literature.
Pulmonary embolism (PE) is a commonly encountered clinical entity in patients with coronavirus disease 2019 (COVID-19). Up to 1/3 of patients have been found to have PE in the setting of COVID-19. ...Given the novelty of the virus causing this pandemic, it has not been easy to address diagnostic and management issues in PE. Ongoing research and publications of the scientific literature have helped in dealing with COVID-19 lately and this applies to PE as well. In this article, we attempt to succinctly yet comprehensively discuss PE in patients with COVID-19 with a review of the prevailing literature.
•Here, we demonstrate thermoelectric performance of allotropic TeSe2.•We confirm the energetic and kinetic stability of five TeSe2 allotropes.•δ-TeSe2 is found a new direct band gap semiconductor ...(Eg = 1.60 eV).•Figure of merit (ZT) can reach up to 3.1 with p-type doping in δ-TeSe2.•Temperature and chemical potential tuning extends the thermoelectric performance of TeSe2 allotropes.
The waste heat management becomes very important with increasing energy demand and limited fossil resources. Here, we demonstrate thermoelectric performance of allotropic TeSe2. Based on the first-principle calculations, we confirm the energetic and kinetic stability of five TeSe2 allotropes. We predict δ-TeSe2 as a new direct band gap semiconductor having 1.60 eV direct band gap. All the TeSe2 allotropes exhibit band gap in UV–Vis region. The structural phases are clearly distinguished using simulated scanning tunneling microscopy. The room temperature Seeback coefficient is maximum of 4 mV/K for δ-TeSe2. We show that room temperature thermoelectric figure of merit (ZT) can reach up to 3.1 with p-type doping in δ-TeSe2. Moreover, temperature and chemical potential tuning extends the thermoelectric performance of TeSe2 allotropes. We strongly believe that our study is compelling from an experimental perspective and holds a key towards fabrication of thermoelectric devices based on TeSe2.
The environmental oxygen and water interaction-driven modulations in structural, electronic, and optical properties of sigma tellurene have been reported. The oxygen interacts strongly with sigma ...tellurene and energy gain during the interaction suggests the expected slow degradation of sigma tellurene. A band gap opening of about 68 meV occurs in tellurene in the presence of environmental oxygen and water. The O2 significantly increases the quantum capacitance of interacting tellurene with a maximum value of 96.07 μFcm−2 with an applied potential of −0.8 V. An observable modulation in the optical response of interacting tellurene occurs in the IR region. The O2 interaction enhances absorption with a maximum blue shift of 120 meV in the imaginary part of the dielectric function. Our study provides significant pointers to determine the aging effects in tellurene based devices.
•The oxygen interacts strongly with sigma tellurene.•The energy gain during the interaction suggests expected slow degradation of sigma tellurene.•Dirac cone disappears and a band gap of 68 meV open up in the presence of environmental oxygen and water.•The optical responses of interacting tellurene get modulated in the IR region.•Present study is beneficial to determine the aging effects in tellurene based devices.
The Hydrogen and Fluorine planar armchairs graphene nanoribbons (H
&
F AGNRs), subjected to twist deformation within fixed periodic boundary conditions. H-AGNRs is highly elastic in nature, though ...passivation with Fluorine does induce the plasticity when twisted beyond threshold torsional strain. This plasticity attributes to the wider bond length distribution suggests distortion of benzo-rings. The bandgap response to the effective strain of narrow GNRs
N
=
6
,
7
, and 8 get arranged as (
i
) monotonously increasing for
q
=
0
,
2
and (
ii
) decreasing for
q
=
1
; here,
q
=
m
o
d
N
,
3
in effective strain space
(
θ
2
Σ
2
)
. The effective strain space is found to be more appropriate for gauging the response of torsional strain. This trend has also been observed for Fluorine passivated AGNRs; however, because of higher sensitive response to torsional strain, the bandgap of
N
=
7 F-AGNRs drops from
E
g
≃
0.95
eV
to
E
g
≃
0.05
eV
at extreme torsional strain forming Dirac cone at
±
K
allows dissipationless transport to charge carriers of high kinetic energy at low bias.
Graphic abstract
Nanostructured zinc sulfide can provide unique photonic, electronic, and catalytic properties that are of interest for applications ranging from bioimaging to photocatalysis. Here we report an easily ...controllable continuous method to produce porous and hollow ZnS nano- and microspheres. We used poly(ethylene glycol) methyl ether (PEG), polyvinylpyrrolidone (PVP), ethylene oxide/propylene oxide block copolymer (Pluronic F-38), and cetyltrimethylammonium bromide (CTAB) as templates to synthesize ZnS nano- and microspheres with controlled internal morphology in a spray pyrolysis process, starting from an aqueous solution of chemical precursors and templating agents. Spherical particles were produced by droplet-to-particle conversion of droplets. Zinc acetate and thiourea, used here as precursors for ZnS, react in solution to form bis-thiourea zinc acetate (BTZA), which precipitates with the evaporation of solvent. Upon further heating, BTZA decomposes to yield ZnS. During solvent evaporation, PEG and Pluronic precipitate after BTZA, driving formation of a shell of ZnS and a hollow core. In contrast, PVP and CTAB interact strongly with BTZA and ZnS, such that the PVP and ZnS remain intermixed. After evaporation of solvent, the templating agents can be pyrolyzed at high temperature to leave behind porous or hollow ZnS microspheres composed of many much smaller nanocrystals.
The pentakis(2,4-dimethylphenoxo) niobium (V) complex of composition Nb(OC6H3(CH3)2-2,4)5 has been synthesized by the reaction of niobium pentachloride with 2,4-dimethylphenol in 1:5 M ratio in CCl4 ...and characterized by elemental analyses, molar conductivity, molecular weight determination, IR, 1H NMR and mass spectral techniques. The geometrical optimization of the complex has been performed by DFT in SIESTA code using standard conjugate gradient (CG) technique. From bond lengths and bond angles of the optimized structure a trigonal-bipyramidal geometry around niobium has been proposed. The HOMO and LUMO energies were analysed to predict the reactivity of the complex and to evaluate global reactivity descriptors-ionization potential (IP), electron affinity (EA), chemical potential (μ), hardness (η), softness (S), electronegativity (χ) and global electrophilicity index (ω). The molecular orbital contributions have been analysed from the total density of states (TDOS), partial density of states (PDOS) and crystal orbital Hamilton populations (COHPs). The thermal behaviour of the complex studied by TG and DTA techniques has indicated it to decompose in single step yielding Nb2O5 as the decomposition product authenticated by IR spectra. The kinetic and thermodynamic parameters from TG data have been computed using Coats–Redfern and Achar equations and F1 first order random nucleation mechanism has been deduced.
Display omitted
We synthesized hollow core–satellite nanoassemblies comprised of hollow zinc sulfide (ZnS) shells decorated with silver nanoparticles (Ag NPs). This was achieved by solution-phase ...attachment of Ag NPs to hollow ZnS nanospheres (NSs) prepared by spray pyrolysis. This produces an aqueous dispersion of ZnS–Ag hybrid structures, 50–500nm in overall diameter. We characterized the nanostructures by scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), and energy dispersive X-ray spectroscopy (EDX) to elucidate the ZnS (core)–Ag (satellite) morphology and optimize conditions for producing such structures. Optical spectroscopy showed that photoluminescence of ZnS was quenched by Ag while absorbance was enhanced. This work provides a simple and general means of producing hollow core–satellite structures that could be of broad applicability.
In May of 2016, a 37-years-old Hispanic female, with no significant past medical history was brought to our hospital with right-sided chest pain. Chest X ray revealed large right pneumothorax (A) and ...she underwent chest tube placement. Computed tomography (CT) chest without contrast showed innumerable cysts in the upper and lower lobes of bilateral lungs (B) and right thoracostomy tube with very small residual pneumothorax (C). CT abdomen showed hyperdense mass in left and possibly right kidney (D). CT head without contrast showed small calcifications in the lateral ventricles suggestive of tubers (E). A diagnosis of lymphangioleiomyomatosis (LAM) was suspected. Serum vascular endothelial growth factor D was 800 pg/ml. She underwent open lung biopsy and diagnosis of LAM was established after histopathologic evaluation. Patient was sent to LAM clinic at a higher center and was started on sirolimus with an aim to stabilize her lung function, improve quality of life and functional performance. Since, sirolimus is used for suppressive rather than curative intent, patient has had 4 more episodes of spontaneous pneumothoaraces in last four years. Her last admission was in May of 2020 due to left sided secondary spontaneous pneumothorax (F), which completely resolved in 2 weeks without chest tube insertion (G).
PDF
