Catalytic Dehydrogenation of Formic Acid Promoted by Triphos-Co Complexes: Two Competing Pathways for H2 Production.

In this study, we reported the synthesis and structural characterization of a triphos-CoII complex [(κ3-triphos)CoII(CH3CN)2]2+ (1) and a triphos-CoI-H complex [(κ2-triphos)HCoI(CO)2] (4). The facile synthetic pathways from 1 to [(κ3-triphos)CoII(κ2-O2CH)]+ (1') and [(κ3-triphos)CoI(CH3CN)]+ (2), respectively, as well as the interconversion between [(κ3-triphos)CoI(CO)2]+ (3) and 4 have been established. The activation energy barrier, associated with the dehydrogenation of a coordinated formate fragment in 1' yielding the corresponding 2 accompanied by the formation of H2 and CO2, was experimentally determined as 23.9 kcal/mol. With 0.01 mol % loading of 1, a maximum TON ∼ 1735 within 18 h and TOF ∼ 483 h-1 for the first 3 h could be achieved. Kinetic isotope effect (KIE) values of 2.25 (kHCOOH/kDCOOH) and 1.36 (kHCOOH/kHCOOD) for the dehydrogenation of formic acid and its deuterated derivatives, respectively, implicate that the H-COOH bond cleavage is likely the rate-determining step. The catalytic mechanism proposed by density functional theory (DFT) calculations coupled with experimental 1H NMR and gas chromatography-mass spectrometry (GC-MS) analysis unveils two competing pathways for H2 production; specifically, deprotonating a HCOO-H bond by a proposed Co-H intermediate C and homolytic cleavage of the CoII-H moiety of C, presumably via a dimeric Co intermediate D containing a [Co2(µ-H)2]2+ core, to yield the corresponding 2 and H2.

Honeycomb layered oxides: structure, energy storage, transport, topology and relevant insights.

The advent of nanotechnology has hurtled the discovery and development of nanostructured materials with stellar chemical and physical functionalities in a bid to address issues in energy, environment, telecommunications and healthcare. In this quest, a class of two-dimensional layered materials consisting of alkali or coinage metal atoms sandwiched between slabs exclusively made of transition metal and chalcogen (or pnictogen) atoms arranged in a honeycomb fashion have emerged as materials exhibiting fascinatingly rich crystal chemistry, high-voltage electrochemistry, fast cation diffusion besides playing host to varied exotic electromagnetic and topological phenomena. Currently, with a niche application in energy storage as high-voltage materials, this class of honeycomb layered oxides serves as ideal pedagogical exemplars of the innumerable capabilities of nanomaterials drawing immense interest in multiple fields ranging from materials science, solid-state chemistry, electrochemistry and condensed matter physics. In this review, we delineate the relevant chemistry and physics of honeycomb layered oxides, and discuss their functionalities for tunable electrochemistry, superfast ionic conduction, electromagnetism and topology. Moreover, we elucidate the unexplored albeit vastly promising crystal chemistry space whilst outlining effective ways to identify regions within this compositional space, particularly where interesting electromagnetic and topological properties could be lurking within the aforementioned alkali and coinage-metal honeycomb layered oxide structures. We conclude by pointing towards possible future research directions, particularly the prospective realisation of Kitaev-Heisenberg-Dzyaloshinskii-Moriya interactions with single crystals and Floquet theory in closely-related honeycomb layered oxide materials.

Oestrogen-induced angiogenesis promotes adenomyosis by activating the Slug-VEGF axis in endometrial epithelial cells.

Adenomyosis is an oestrogen-dependent disease characterized by the invasion of endometrial epithelial cells into the myometrium of uterus, and angiogenesis is thought to be required for the implantation of endometrial glandular tissues during the adenomyotic pathogenesis. In this study, we demonstrate that compared with eutopic endometria, adenomyotic lesions exhibited increased vascularity as detected by sonography. Microscopically, the lesions also exhibited an oestrogen-associated elevation of microvascular density and VEGF expression in endometrial epithelial cells. We previously reported that oestrogen-induced Slug expression was critical for endometrial epithelial-mesenchymal transition and development of adenomyosis. Our present studies demonstrated that estradiol (E2) elicited a Slug-VEGF axis in endometrial epithelial cells, and also induced pro-angiogenic activity in vascular endothelial cells. The antagonizing agents against E2 or VEGF suppressed endothelial cells migration and tubal formation. Animal experiments furthermore confirmed that blockage of E2 or VEGF was efficient to attenuate the implantation of adenomyotic lesions. These results highlight the importance of oestrogen-induced angiogenesis in adenomyosis development and provide a potential strategy for treating adenomyosis through intercepting the E2-Slug-VEGF pathway.

Noninvasive prenatal testing for whole fetal chromosomal aneuploidies: a multicenter prospective cohort trial in Taiwan.

OBJECTIVE: To evaluate the performance of noninvasive prenatal testing for all fetal chromosomal aneuploidies in an extremely high-risk group undergoing first trimester combined Down syndrome screening. METHOD: A multicenter cohort prospective study in Taiwan was performed between June and December 2012. Maternal plasma was collected and shotgun massive parallel sequencing was performed on each fetal chromosome. 201 Taiwanese pregnant women at >12 weeks' gestation from 11 medical centers were enrolled in this trial. The extremely high-risk group was defined as a Down syndrome risk cutoff >1:30 or nuchal translucency >3.0 mm (n = 100), while the low-risk group was defined as a Down syndrome cutoff <1:1,500 (n = 101). Amniocentesis confirmation was performed and birth outcome was also recorded. RESULTS: There were 11 cases of trisomy 21, 8 cases of trisomy 18, 3 cases of trisomy 13, 1 case of trisomy 16, 3 cases of 45,X, and 1 case of 47,XYY detected prenatally in 100 extremely high-risk gravidas [n = 27/100 (27%)]. The overall autosomal or sex chromosome aneuploidy detection rate was 96% (27/28) because of an insufficient amount maternal plasma for one fetus with Turner syndrome. In the low-risk group, no chromosomal abnormalities were detected (specificity = 100%). There were no false-positive cases in this study. CONCLUSIONS: This first trial in Taiwan shows that noninvasive prenatal testing for whole chromosome aneuploidies can be efficiently applied in extremely high- and low-risk populations.

Plasmon Tuning of Liquid Gallium Nanoparticles through Surface Anodization.

In this work, tunable plasmonic liquid gallium nanoparticles (Ga NPs) were prepared through surface anodizing of the particles. Shape deformation of the Ga NPs accompanied with dimpled surface topographies could be induced during electrochemical anodization, and the formation of the anodic oxide shell helps maintain the resulting change in the particle shape. The nanoscale dimple-like textures led to changes in the localized surface plasmon resonance (LSPR) wavelength. A maximal LSPR red-shift of ~77 nm was preliminarily achieved using an anodization voltage of 0.7 V. The experimental results showed that an increase in the oxide shell thickness yielded a negligible difference in the observed LSPR, and finite-difference time-domain (FDTD) simulations also suggested that the LSPR tunability was primarily determined by the shape of the deformed particles. The extent of particle deformation could be adjusted in a very short period of anodization time (~7 s), which offers an efficient way to tune the LSPR response of Ga NPs.

The sex-specific association of prenatal phthalate exposure with low birth weight and small for gestational age: A nationwide survey by the Taiwan Maternal and Infant Cohort Study (TMICS).

The Taiwan Maternal and Infant Cohort Study (TMICS) was launched with the aim to assess the effects of prenatal exposure to phthalic acid esters (PAEs) on infant health. A total of 1102 pregnant women were enrolled in this study from 2012 to 2015. All participants completed a structured questionnaire, and provided urine specimens. The urinary concentrations of PAE metabolites in the third trimester were measured using liquid chromatography-electrospray ionization tandem mass spectrometry. Generalized additive model-penalized regression splines and logistic regression models were employed to determine the risk for low birth weight (LBW) or small for gestational age (SGA) among pregnant women exposed to PAEs. After adjustments for other covariates, each incremental unit of ln-transformed mono-n-butyl phthalate (MnBP) for pregnant women increased the odds of SGA in male neonates by 1.44 (95% CI: 0.92-2.23). An inverse association between SGA and maternal MnBP exposure level was observed in female neonates. An increase in one ln-transformed MnBP concentration unit decreased the risk of female SGA to 0.50 (95% CI: 0.24-0.97). In the penalized regression splines, increased risks of LBW/SGA in male neonates were presented while pregnant women exposed to increased MnBP levels. However, an association in the opposite direction was observed between maternal MnBP and LBW or SGA for male and female neonates. This study indicated that high maternal MnBP exposure in the third trimester was associated with LBW or SGA for male infants. Adverse effects on susceptible populations exposed to high levels of PAEs should be of concern.

Mixed alkali-ion transport and storage in atomic-disordered honeycomb layered NaKNi2TeO6.

Honeycomb layered oxides constitute an emerging class of materials that show interesting physicochemical and electrochemical properties. However, the development of these materials is still limited. Here, we report the combined use of alkali atoms (Na and K) to produce a mixed-alkali honeycomb layered oxide material, namely, NaKNi2TeO6. Via transmission electron microscopy measurements, we reveal the local atomic structural disorders characterised by aperiodic stacking and incoherency in the alternating arrangement of Na and K atoms. We also investigate the possibility of mixed electrochemical transport and storage of Na+ and K+ ions in NaKNi2TeO6. In particular, we report an average discharge cell voltage of about 4 V and a specific capacity of around 80 mAh g-1 at low specific currents (i.e., < 10 mA g-1) when a NaKNi2TeO6-based positive electrode is combined with a room-temperature NaK liquid alloy negative electrode using an ionic liquid-based electrolyte solution. These results represent a step towards the use of tailored cathode active materials for "dendrite-free" electrochemical energy storage systems exploiting room-temperature liquid alkali metal alloy materials.

Inorganic AlCl3-alkali metal thiocyanate ionic liquids as electrolytes for electrochemical Al technologies.

A series of inorganic AlCl3-alkali metal thiocyanate (AMSCN: AM = Li, Na, K) ionic liquids (ILs) are demonstrated as electrolytes for Al electrodeposition and Al-anion rechargeable batteries (AARBs) at 303-363 K. Al deposits with a unique flake nanostructure are obtained in these electrolytes. The assembled AARBs show a stable cyclability over 250 cycles with a reversible capacity of ca. 70 mA h (g-graphite)-1 at 363 K. These inorganic ILs inherit the advantages of conventional chloroaluminate ILs (applicability at near-ambient temperature) and molten salts (cost effectiveness), making them promising electrolyte candidates for industrializable electrochemical Al technologies.

Potassium Difluorophosphate as an Electrolyte Additive for Potassium-Ion Batteries.

The limited cyclability and inferior Coulombic efficiency of graphite negative electrodes have been major impediments to their practical utilization in potassium-ion batteries (PIBs). Herein, for the first time, potassium difluorophosphate (KDFP) electrolyte additive is demonstrated as a viable solution to these bottlenecks by facilitating the formation of a stable and K+-conducting solid-electrolyte interphase (SEI) on graphite. The addition of 0.2 wt % KDFP to the electrolyte results in significant improvements in the (de)potassiation kinetics, capacity retention (76.8% after 400 cycles with KDFP vs 27.4% after 100 cycles without KDFP), and average Coulombic efficiency (∼99.9% during 400 cycles) of the graphite electrode. Moreover, the KDFP-containing electrolyte also enables durable cycling of the K/K symmetric cell at higher efficiencies and lower interfacial resistance as opposed to the electrolyte without KDFP. X-ray diffraction and Raman spectroscopy analyses have confirmed the reversible formation of a phase-pure stage-1 potassium-graphite intercalation compound (KC8) with the aid of KDFP. The enhanced electrochemical performance by the KDFP addition is discussed based on the analysis of the SEI layer on graphite and K metal electrodes by X-ray photoelectron spectroscopy.

Potassium Single Cation Ionic Liquid Electrolyte for Potassium-Ion Batteries.

Potassium-ion batteries (PIBs) are a promising post-lithium-ion battery (LIB), as their resources are abundant and low-cost and may have a higher voltage than LIBs. However, the high operating voltage and extremely high reactivity of potassium metal require a chemically safe electrolyte with oxidative and reductive stabilities. In this study, a potassium single cation ionic liquid (K-SCIL), which contains only K+ as the cationic species and has a high electrochemical stability, low flammability, and low vapor pressure, is developed as an electrolyte for PIBs. The mixture of potassium bis(fluorosulfonyl)amide and potassium (fluorosulfonyl)(trifluoromethylsulfonyl)amide at a molar ratio of 55:45 had the lowest melting point of 67 °C. The K+ concentration in this K-SCIL is high (8.5 mol dm-3 at 90 °C) due to the absence of solvents and bulky organic cations. In addition, the electrochemical window is as wide as 5.6 V, which enables the construction of PIBs with a high energy density. A high current density can be achieved with this K-SCIL, owing to the absence of a K+ concentration gradient. The electrolyte was successfully used with a graphite negative electrode, enabling the reversible intercalation/deintercalation of K+, as confirmed by X-ray diffraction.

Fabrication of local micro-contacts to silicon solar cells by dewetting of ultrathin polymer films.

A local contact patterning process based on dewetting of 50 nm-thick polystyrene (PS) films has been developed for fabrication of silicon PERC (Passivated Emitter and Rear Cell) solar cells. Holey PS films with a random pattern of holes were prepared on dielectric passivated silicon wafers through the dewetting process, and then served as etch masks for selective plasma etching of dielectric passivation layers, in doing so metal contact patterns could be generated. The impact of local back contact formation on cell performance was studied as a function of the metallization fraction. This chemical-based patterning process, which broadens the applications of dewetting of polymer films, offers an interesting alternative to laser-based approaches as it may avoid silicon surface damage and lower the manufacturing costs. The application of this patterning technique to PERC fabrication could result in a preliminary efficiency of 13.5% with a V oc = 655 mV and a J sc = 38.4 mA cm-2. An apparent gain in conversion efficiency of 0.6% could be achieved compared to the full-area aluminum back surface field reference cell.

High-voltage honeycomb layered oxide positive electrodes for rechargeable sodium batteries.

Honeycomb layered oxides from Na2Ni2-xCoxTeO6 family were assessed for use as positive electrodes in rechargeable sodium batteries at ambient and elevated temperatures using ionic liquids. Substitution of nickel with cobalt increases the discharge voltage to nearly 4 V (versus Na+/Na), surpassing the average voltages of most Na based layered oxide positive electrodes.

A Zinc-Dual-Halogen Battery with a Molten Hydrate Electrolyte.

Halogen redox couples offer several advantages for energy storage such as low cost, high solubility in water, and high redox potential. However, the operational complexity of storing halogens at the oxidation state via liquid-phase media hampers their widespread application in energy-storage devices. Herein, an aqueous zinc-dual-halogen battery system taking the advantages of redox flow batteries (inherent scalability) and intercalation chemistry (high capacity) is designed and fabricated. To enhance specific energy, the designed cell exploits both bromine and chlorine as the cathode redox couples that are present as halozinc complexes in a newly developed molten hydrate electrolyte, which is distinctive to the conventional zinc-bromine batteries. Benefiting from the reversible uptake of halogens at the graphite cathode, exclusive reliance on earth-abundant elements, and membrane-free and possible flow-through configuration, the proposed battery can potentially realize high-performance massive electric energy storage at a reasonable cost.

Decorating carbon nanotubes with nanoparticles using a facile redox displacement reaction and an evaluation of synergistic hydrogen storage performance.

A facile displacement reaction is proposed for decorating multi-walled carbon nanotubes (CNTs) with nanoparticles. The Sn(II-->IV)/Pd(II-->0) redox couple is used as an example; the Sn(II) pre-treated CNTs reacted with Pd(II)-containing solution to produce a Pd/CNT composite. The two-step process, with the aid of ultrasonication, can produce nano-sized particles that are uniformly dispersed and tightly anchored on the surfaces of CNTs. The proposed synthesis protocol does not need sophisticated equipment, making it low-cost. Large-scale production should be realizable. The constructed heterostructure exhibits a synergistic effect in its hydrogen storage performance, which was evaluated using a high-pressure microbalance. The deposited Pd-based nanoparticles enhanced the spillover reaction on CNTs, doubling the amount of hydrogen adsorbed at room temperature as compared to pristine CNTs.

Prenatal diagnosis of tetralogy of Fallot with pulmonary atresia.

Tetralogy of Fallot involves an abnormal embryological development in which an unequal conotruncal division results in a small pulmonary artery and a great aortic artery. In its most severe form, the infundibulum of the right ventricle and the pulmonary artery can be atretic with the anomaly commonly referred to as pulmonary atresia with ventricular septal defect. Reported here is a case of prenatal diagnosis of tetralogy of Fallot with pulmonary atresia. The characteristic ultrasonographic findings included a small pulmonary artery, a large aorta, and a ventricular septal defect. The search for an atretic pulmonary valve and a ductus arteriosus with reversed blood flow was emphasized in the presence of asymmetrically dilated fetal heart. After birth, the newborn received single-stage total correction for the tetralogy of Fallot and was discharged a month later in stable condition. In this case report, the neonatal angiogram is added for confirming the prenatal diagnosis, which is of value in teaching fetal echocardiography to novice practitioners. We believe a prenatal diagnosis of tetralogy of Fallot can improve neonatal outcome.

Hyperbaric oxygen therapy for cesarean section wound in diabetes mellitus gravida.

We report the use of hyperbaric oxygen (HBO) therapy to treat the complication of necrotizing fasciitis following Cesarean section in a postpartum gravida with diabetes mellitus. Our patient was a 25-year-old, gravida 1, para 1, woman with a history of type 1 diabetes mellitus since the age of 18. The patient experienced preterm labor at 31+1 gestational weeks and was treated with magnesium sulfate for tocolytic therapy. The patient then went into labor at 39+6 gestational weeks. She received Cesarean section due to prolonged labor associated with non-reassuring fetal status of both smooth baseline and fetal tachycardia. An ultrasound scan of the lower abdomen on the 4th postoperative day revealed fluid collection measuring 4 mm over the rectus fascia and edematous change of the surrounding soft tissues under the Cesarean section incision site. The patient eventually received HBO for a total of 7 days. Following HBO, the condition of the surgical wound improved dramatically. The results of this case showed that HBO has the potential to be a cost-effective way to enhance the healing of necrotizing fasciitis in diabetes mellitus gravida.

Prenatal diagnosis of pulmonary sequestration by ultrasound and magnetic resonance imaging.

A 36-year-old multigravida, G2P1, underwent routine ultrasound scan at 22+1 weeks of gestation, which revealed a single normally growing fetus with left intrathoracic mass and left displacement of the cardiac apex. The left intrathoracic wedge-shaped hyperechogenic mass, measuring 32 x 25 mm in size, was situated at the lower portion of the left lung. A combination of color and power Doppler ultrasound allowed visualization of a vessel arising from the descending aorta, which supplied the mass. The diagnosis of extralobar pulmonary sequestration was made. Magnetic resonance imaging (MRI) was also performed and revealed a well-defined mass with homogeneous high-signal intensity when compared with normal lung tissue in the left upper lung field, which was compatible with pulmonary sequestration. The pulmonary mass was followed up by color and power Doppler every 2 weeks. The peak velocity of 11.85 cm/sec and the diameter of the feeding artery of 1.19 mm gradually decreased and disappeared 8 weeks later. The intrathoracic mass disappeared 10 weeks later at 32+1 gestational weeks. Repeat MRI also revealed spontaneous regression of the mass in favor of resorption of sequestration. The fetus was delivered at 38+1 gestational weeks. A male newborn weighing 2,520 g was spontaneously delivered with an Apgar score of 8 at 1 minute and 9 at 5 minutes. In our patient, it is suggested that progressive decreases in the peak velocity of the feeding vessel heralded the spontaneous regression of pulmonary sequestration not associated with hydrops/hydrothorax.

Prenatal diagnosis of dextrotransposition of the great arteries.

Dextrotransposition of the great arteries (DTGA) is a common cardiac cause of cyanosis in newborn infants that can cause acidosis and death within a short period of time unless there is a large atrial-level shunt or a patent ductus arteriosus. Here, we report a case of prenatal diagnosis of DTGA at 24+1 gestational weeks. In a tilted 4-chamber view, the pulmonary trunk branched to the left and the right pulmonary, with its root connected to the left ventricle outflow tract. In the short-axis view, the pulmonary trunk was shown to be parallel with the ascending aortic root. Cesarean section was performed due to the nonreassuring fetal status at 38+5 gestational weeks. The male neonate appeared to have mild cyanotic symptoms and weighed 3,108 g. Apgar scores were 8 and 9 at 1 and 5 minutes, respectively. Neonatal echocardiography was performed immediately after birth and the findings confirmed DTGA associated with atrial septal defect secundum. Postnatally, angiography confirmed the echocardiographic diagnosis of DTGA with a large atrial septal defect secundum and a large patent ductus arteriosus. Jatene arterial switch operation and atrial septal defect closure with Gore-Tex patch were performed. The neonate withstood the operation well and was discharged 27 days after birth weighing 2,950 g and in a stable condition. Prenatal diagnosis of DTGA can greatly aid to prepare the patient's family and the surgeon and significantly improve the outcome of complex heart disease in the neonatal period.

Lamivudine therapy in the treatment of chronic hepatitis B with acute exacerbation during pregnancy.

We report a case of chronic hepatitis B carrier gravida who had acute exacerbation during pregnancy. She had been taking lamivudine 100 mg/qd for 17 months when hepatitis B virus (HBV) DNA in the YMDD region of the polymerase gene (YMDD motif) mutant was noted. After discontinuing lamivudine, she became pregnant. HBeAg became positive again and liver enzymes were elevated during the first trimester of pregnancy. She received the hepatoprotective agent silymarin 150 mg bid at 13+2 gestational weeks. Serum aspartate aminotransferase (AST) dropped to 757 U/L at 15+0 gestational weeks, but serum alanine aminotransferase (ALT) flared up to 2,230 U/L and AST to 2,250 U/L at 17+1 gestational weeks. Serum HBV-DNA test revealed serum HBV-DNA concentration of 7.31 x 10(8) copies/mL. Lamivudine 100 mg/qd and silymarin 150 mg/bid were initiated at 17+1 gestational weeks. Liver function showed gradual decline to ALT 341 U/L and AST 91 U/L at 21+0 gestational weeks, while HBeAg(+) converted to (-) and anti-HBe(-) converted to (+). Further treatment with lamivudine 100 mg/qd continued for 3 months. Serum HBV-DNA concentrations decreased to 3.19 x 10(2) copies/mL at 36+6 gestational weeks. Spontaneous delivery of a male baby weighing 3314 g occurred at 38+3 gestational weeks. The neonatal physical check-up revealed no congenital anomalies, and fetal growth was within normal reference ranges, suggesting that lamivudine may be safely used in the treatment of chronic hepatitis B with acute exacerbation during the second trimester of pregnancy.