The efficacy and safety of maternal tenofovir disoproxil fumarate (TDF) in reducing mother‐to‐infant hepatitis B virus (HBV) transmissions is not clearly understood. We conducted a prospective, ...multicenter trial and enrolled 118 hepatitis B surface antigen (HBsAg)– and hepatitis B e antigen–positive pregnant women with HBV DNA ≥7.5 log10 IU/mL. The mothers received no medication (control group, n = 56, HBV DNA 8.22 ± 0.39 log10 IU/mL) or TDF 300 mg daily (TDF group, n = 62, HBV DNA 8.18 ± 0.47 log10 IU/mL) from 30‐32 weeks of gestation until 1 month postpartum. Primary outcome was infant HBsAg at 6 months old. At delivery, the TDF group had lower maternal HBV DNA levels (4.29 ± 0.93 versus 8.10 ± 0.56 log10 IU/mL, P < 0.0001). Of the 121/123 newborns, the TDF group had lower rates of HBV DNA positivity at birth (6.15% versus 31.48%, P = 0.0003) and HBsAg positivity at 6 months old (1.54% versus 10.71%, P = 0.0481). Multivariate analysis revealed that the TDF group had lower risk (odds ratio = 0.10, P = 0.0434) and amniocentesis was associated with higher risk (odds ratio 6.82, P = 0.0220) of infant HBsAg positivity. The TDF group had less incidence of maternal alanine aminotransferase (ALT) levels above two times the upper limit of normal for ≥3 months (3.23% versus 14.29%, P = 0.0455), a lesser extent of postpartum elevations of ALT (P = 0.007), and a lower rate of ALT over five times the upper limit of normal (1.64% versus 14.29%, P = 0.0135) at 2 months postpartum. Maternal creatinine and creatinine kinase levels, rates of congenital anomaly, premature birth, and growth parameters in infants were comparable in both groups. At 12 months, one TDF‐group child newly developed HBsAg positivity, presumably due to postnatal infection and inefficient humoral responses to vaccines. Conclusions: Treatment with TDF for highly viremic mothers decreased infant HBV DNA at birth and infant HBsAg positivity at 6 months and ameliorated maternal ALT elevations. (Hepatology 2015;62:375–386
Summary
Background
Maternal anti‐viral treatment prevents mother‐to‐infant transmission of hepatitis B virus (HBV), but the role of neonatal viremia on subsequent HBV infection is not clear.
Aims
To ...investigate the effect of maternal anti‐viral treatment on neonatal serum HBV DNA and hepatitis B surface antigen (HBsAg) in infants born to highly viremic mothers and the roles of neonatal markers in predicting chronic HBV infection in children.
Methods
Serum HBV DNA and HBsAg were tested in children. Of the 201 pregnant mothers, 110 received tenofovir during the third trimester. Chronic infection in children was defined by HBsAg seropositivity at 6 or 12 months lasting more than 6 months.
Results
The maternal HBV viral loads from baseline to delivery were 8.25 ± 0.48 to 4.29 ± 0.98 log10 IU/mL; and 8.29 ± 0.49 to 8.12 ± 0.68 log10 IU/mL in the tenofovir and control group respectively. Of the 208 children, those in the tenofovir group had a lower rate of neonatal HBV DNA seropositivity at birth (5.22% vs 30.11%, P < 0.0001) and HBsAg seropositivity at 6 months (1.74% vs 11.83%, P = 0.003) and 12 months (1.74% vs 10.75%, P = 0.007). In a first multivariate analysis, maternal HBV DNA level at delivery (odds ratio = 1.70, P = 0.0172) and neonatal HBsAg positivity (odds ratio = 19.37, P < 0.0001) were significantly associated with children's chronic HBV infection. In a second model, neonatal HBV DNA positivity was a strong independent influence variable (odds ratio = 61.89, P = 0.0002).
Conclusions
Maternal tenofovir therapy decreased maternal viral load and neonatal viremia. Positive neonatal HBV DNA was highly correlated with chronic HBV infection in children. Clinical Trial Identifier: NCT01312012.
Two-dimensional (2D) Dion–Jacobson (DJ) perovskite solar cells (PSCs), despite their advantage in versatility of n-layer variation, are subject to poor photovoltaic efficiency, particularly in the ...fill factor (FF), compared to their three-dimensional counterparts. To enhance the performance of DJ PSCs, the process of growing crystals and hence the corresponding morphology of DJ perovskites are of prime importance. Herein, we report the fast nonisothermal (NIT) crystallization protocol that is previously unrecognized for 2D perovskites to significantly improve the morphology, orientation, and charge transport of the DJ perovskite films. Comprehensive mechanistic studies reveal that the NIT effect leads to the secondary crystallization stage, forming network-like channels that play a vital role in the FF’s leap-forward improvement and hence the DJ PSC’s performance. As a whole, the NIT crystallized PSCs demonstrate a high power conversion efficiency and an FF of up to 19.87 and 86.16%, respectively. This research thus provides new perspectives to achieve highly efficient DJ PSCs.
Tin‐based perovskite, which exhibits narrower bandgap and comparable photophysical properties to its lead analogs, is one of the most forward‐looking lead‐free semiconductor materials. However, the ...poor oxidative stability of tin perovskite hinders the development toward practical application. In this work, the effect of pseudohalide anions on the stability and emission properties of single‐layer 2D tin perovskite nanoplates with chemical formula TEA2SnI4 (TEA = 2‐thiophene‐ethylammonium) is reported. The results reveal that ammonium thiocyanate (NH4SCN) is the most effective additive in enhancing the stability and photoluminescence quantum yield of 2D TEA2SnI4 (23 ± 3%). X‐Ray photoelectron spectroscopic investigations on the thiocyanate passivated TEA2SnI4 nanoplate show less than a 1% increase of Sn4+ signal upon 30 min exposure to air under ambient conditions (298 K, humidity ≈70%). Furthermore, no noticeable decrease in emission intensity of the nanoplate is observed after 20 h in air. The SCN‐ passivation during the growth stage of TEA2SnI4 is proposed to play a crucial role in preventing the oxidation of Sn2+ and hence boosts both stability and photoluminescence yield of tin perovskite nanoplates.
Ammonium thiocyanate (NH4SCN) is introduced during the synthesis of TEA2SnI4 as a surface passivation reagent to mitigate Sn2+ oxidation, yielding the air‐stable tin perovskite nanomaterials with a core–shell like structure. The thiocyanate‐passivated tin perovskite nanoplates display photoluminescence quantum yield as high as 23% ± 3% and remain luminescent for 24 h after exposure to air.
At the National Synchrotron Radiation Research Center, a small/wide‐angle X‐ray scattering (SAXS/WAXS) instrument has been installed at the BL23A beamline with a superconducting wiggler insertion ...device. This beamline is equipped with double Si(111) crystal and double Mo/B4C multilayer monochromators, and an Si‐based plane mirror that can selectively deflect the beam downwards for grazing‐incidence SAXS (GISAXS) studies of air–liquid or liquid–liquid interfaces. The SAXS/WAXS instrument, situated in an experimental hutch, comprises collimation, sample and post‐sample stages. Pinholes and slits have been incorporated into the beam collimation system spanning a distance of ∼5 m. The sample stage can accommodate various sample geometries for air–liquid interfaces, thin films, and solution and solid samples. The post‐sample section consists of a 1 m WAXS section with two linear gas detectors, a vacuum bellows (1–4 m), a two‐beamstop system and the SAXS detector system, all situated on a motorized optical bench for motion in six degrees of freedom. In particular, the vacuum bellows of a large inner diameter (260 mm) provides continuous changes of the sample‐to‐detector distance under vacuum. Synchronized SAXS and WAXS measurements are realized via a data‐acquisition protocol that can integrate the two linear gas detectors for WAXS and the area detector for SAXS (gas type or Mar165 CCD); the protocol also incorporates sample changing and temperature control for programmable data collection. The performance of the instrument is illustrated via several different measurements, including (1) simultaneous SAXS/WAXS and differential scanning calorimetry for polymer crystallization, (2) structural evolution with a large ordering spacing of ∼250 nm in a supramolecular complex, (3) SAXS for polymer blends under in situ drawing, (4) SAXS and anomalous SAXS for unilamellar lipid vesicles and metalloprotein solutions, (5) anomalous GISAXS for oriented membranes of Br‐labeled lipids embedded with peptides, and (6) GISAXS for silicate films formed in situ at the air–water interface.
A novel application of supramolecular interactions within semicrystalline polymers, capable of self‐assembling into supramolecular polymer networks via self‐complementary multiple hydrogen‐bonded ...complexes, is demonstrated for efficient construction of highly controlled self‐organizing hierarchical structures to offer a direct, efficient nucleation pathway resulting in superior crystallization performance. Herein, a novel functionalized poly(ε‐caprolactone) containing self‐complementary sextuple hydrogen‐bonded uracil‐diamidopyridine (U‐DPy) moieties is successfully developed and demonstrated excellent thermal and viscoelastic properties as well as high dynamic structural stability in the bulk state due to physical cross‐linking created by reversible sextuple hydrogen bonding between U‐DPy units. Due to the ability to vary the extent of the reversible network by tuning the U‐DPy content, this newly developed material can be readily adjusted to obtain the desired crystalline products with specific characteristics. Importantly, incorporating only 0.1% U‐DPy resulted in a polymer with a high crystallization rate constant, short crystallization half‐time, and much more rapid crystallization kinetics than pristine PCL, indicating a low content of U‐DPy moieties provides highly efficient nucleation sites that manipulate the nucleation and growth processes of polymer crystals to promote crystallization and chain alignment in bulk. This new system is suggested as a potential new route to substantially improve the performance of polymer crystallization.
Functional supramolecular polymers can be used to manipulate the nucleation and growth processes of polymer crystals, resulting in substantially enhanced crystallization performance at an ultralow content of sextuple hydrogen‐bonded uracil‐diamidopyridine motifs.
Many EDA applications are extremely sparse, irregular, and control-flow intensive. Parallelizing this type of application can benefit from the ability to express dynamic task parallelism across ...arbitrary decision-making points at runtime. Unlike the traditional construct-and-run models, dynamic task parallelism offers programmers great flexibility to parallelize EDA algorithms that incorporate complex execution logic under dynamic control flow, such as branch-and-bound techniques, on-the-fly pruning, and recursive decomposition strategies. In this paper, we introduce a new programming model that supports the dynamic building of a computational task graph. We will cover scheduling details and best practices for exploring task parallelism under dynamic control flow. We will present a real use case of our model that has successfully parallelized a static timing analysis workload.
Tin-based perovskite, which exhibits narrower bandgap and comparable photophysical properties to its lead analogs, is one of the most forward-looking lead-free semiconductor materials. However, the ...poor oxidative stability of tin perovskite hinders the development toward practical application. In this work, the effect of pseudohalide anions on the stability and emission properties of single-layer 2D tin perovskite nanoplates with chemical formula TEA
SnI
(TEA = 2-thiophene-ethylammonium) is reported. The results reveal that ammonium thiocyanate (NH
SCN) is the most effective additive in enhancing the stability and photoluminescence quantum yield of 2D TEA
SnI
(23 ± 3%). X-Ray photoelectron spectroscopic investigations on the thiocyanate passivated TEA
SnI
nanoplate show less than a 1% increase of Sn
signal upon 30 min exposure to air under ambient conditions (298 K, humidity ≈70%). Furthermore, no noticeable decrease in emission intensity of the nanoplate is observed after 20 h in air. The SCN
passivation during the growth stage of TEA
SnI
is proposed to play a crucial role in preventing the oxidation of Sn
and hence boosts both stability and photoluminescence yield of tin perovskite nanoplates.
PDF
