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Introduction: In pediatric patients with Budd–Chiari syndrome (BCS), living donor liver transplantation (LDLT) raises substantial challenges regarding IVC reconstruction. Case Presentation: We present a case of an 8‐year‐old girl with BCS caused by myeloproliferative syndrome with JAK2 V617F mutation. She had a complete thrombosis of the inferior vena cava (IVC) with multiple collaterals, developing a Budd–Chiari syndrome. She underwent LDLT with IVC reconstruction with a cryopreserved pulmonary vein graft obtained from a provincial biobank. The living donor underwent a laparoscopic‐assisted left lateral hepatectomy. The reconstruction of the vena cava took place on the back table and the liver was implanted en bloc with the reconstructed IVC in the recipient. Anticoagulation was immediately restarted after the surgery because of her pro‐thrombotic state. Her postoperative course was complicated by a biliary anastomotic leak and an infected biloma. The patient recovered progressively and remained well on outpatient clinic follow‐up 32 weeks after the procedure. Conclusion: IVC reconstruction using a cryopreserved pulmonary vein graft is a valid option during LDLT for pediatric patients with BCS where reconstruction of the IVC entails considerable challenges. Early referral to a pediatric liver transplant facility with a multidisciplinary team is also important in the management of pediatric patients with BCS. [ABSTRACT FROM AUTHOR]

In this letter, a simple balanced directional coupler with high common‐mode (CM) suppression is designed by using a single‐layer substrate‐integrated waveguide (SIW). The SIW can be considered a naturally balanced structure. The CM noises are able to be intrinsically suppressed when differentially excited along the symmetric H‐plane of SIW. The coupling window with tapered transition is designed for broadening the bandwidth of 3‐dB coupling. The microstrip differential feeding structure with inductive vias and inductive matching section enables planar integration and better impedance matching. Finally, a SIW balanced directional coupler operating at 14–16 GHz is designed and fabricated. Measured results are in good agreement with simulated ones. [ABSTRACT FROM AUTHOR]

The bacterial nitroreductases (NRs) NfsB and NfsA are conserved homodimeric FMN‐dependent flavoproteins that are responsible for the reduction of nitroaromatic substrates. Berberine (BBR) is a plant‐derived isoquinoline alkaloid with a large conjugated ring system that is widely used in the treatment of various diseases. It was recently found that the gut microbiota convert BBR into dihydroberberine (dhBBR, the absorbable form) mediated by bacterial NRs. The molecular basis for the transformation of BBR by the gut microbiota remains unclear. Here, kinetic studies showed that NfsB from Escherichia coli (EcNfsB), rather than EcNfsA, is responsible for the conversion of BBR to dhBBR in spite of a low reaction rate. The crystal structure of the EcNfsB–BBR complex showed that BBR binds into the active pocket at the dimer interface, and its large conjugated plane stacks above the plane of the FMN cofactor in a nearly parallel orientation. BBR is mainly stabilized by π‐stacking interactions with both neighboring aromatic residues and FMN. Structure‐based mutagenesis studies further revealed that the highly conserved Phe70 and Phe199 are important residues for the conversion of BBR. The structure revealed that the C6 atom of BBR (which receives the hydride) is ∼7.5 Å from the N5 atom of FMN (which donates the hydride), which is too distant for hydride transfer. Notably, several well ordered water molecules make hydrogen‐bond/van der Waals contacts with the N1 atom of BBR in the active site, which probably donate protons in conjunction with electron transfer from FMN. The structure–function studies revealed the mechanism for the recognition and binding of BBR by bacterial NRs and may help to understand the conversion of BBR by the gut microbiota. [ABSTRACT FROM AUTHOR]

Cerium (IV)‐based metal‐organic frameworks (MOFs) are highly desirable due to their unique potential in fields such as redox catalysis and photocatalysis. However, due to the high reduction potential of CeIV species in solution, it is still a great challenge to synthesize CeIV‐MOFs with novel structures, which are extremely dominated by the hexanuclear Ce−O cluster inorganic building units (IBUs). Herein, a Ce−O IBU chain containing CeIV‐MOF, CSUST‐3 (CSUST: Changsha University of Science and Technology), was successfully prepared using the kinetic stabilization study of UiO‐66(Ce)‐NDC (H2NDC=2,6‐naphthalenedicarboxylic acid). Furthermore, owing to the superior redox activity, Lewis acidity and semiconductor‐like behavior owing to Ce4+, activated CSUST‐3 was demonstrated to be an excellent catalyst for CO2 chemical fixation. One‐pot synthesis of styrene carbonate from styrene and CO2 was achieved under mild conditions (1 atm CO2, 80 °C, and solvent free). Moreover, activated CSUST‐3 was shown to be a remarkable co‐catalyst‐free photocatalyst for overall water splitting (OWS), rendering 59 μmol g−1 h−1 of H2 and 22 μmol g−1 h−1 of O2 under simulated sunlight irradiation (Na2S‐Na2SO3 as sacrificial agent). [ABSTRACT FROM AUTHOR]

Evidence in the literature suggests that air pollution exposure affects outcomes of patients with COVID‐19. However, the extent of this effect requires further investigation. This study was designed to investigate the relationship between long‐term exposure to air pollution and the case fatality rate (CFR) of patients with COVID‐19. The data on air quality index (AQI), PM2.5, PM10, SO2, NO2, and O3 from 14 major cities in China in the past 5 years (2015–2020) were collected, and the CRF of COVID‐19 patients in these cities was calculated. First, we investigated the correlation between CFR and long‐term air quality indicators. Second, we examined the air pollutants affecting CFR and evaluated their predictive values. We found a positive correlation between the CFR and AQI (1, 3, and 5 years), PM2.5 (1, 3, and 5 years), and PM10 (1, 3, and 5 years). Further analysis indicated the more significant correlation for both AQI (3 and 5 years) and PM2.5 (1, 3, and 5 years) with CFR, and moderate predictive values for air pollution indicators such as AQI (1, 3, and 5 years) and PM2.5 (1, 3, and 5 years) for CFR. Our results indicate that long‐term exposure to severe air pollution is associated with higher CFR of COVID‐19 patients. Air pollutants such as PM2.5 may assist with the prediction of CFR for COVID‐19 patients. [ABSTRACT FROM AUTHOR]

Methotrexate (MTX) pharmacokinetics has substantial inter‐individual variability and toxicity. In children with medulloblastoma treated with high‐dose methotrexate (HD‐MTX), the pharmacokinetic properties of methotrexate have not been established. A total of 660 serum samples from 105 pediatric patients with medulloblastoma were included in a population pharmacokinetic (PPK) analysis of methotrexate by using the nonlinear mixed‐effects modeling method. The basic one‐compartment population pharmacokinetic model was established by NONMEM software and the first‐order conditional estimation (FOCE) method, and the final covariate model was obtained by the stepwise regression method. Weight (WT), creatinine clearance (CrCL), and whether the treatment was combined with dexamethasone (DEX) were covariates that had significant effects on the clearance rate (CL) of the model. The pharmacokinetic equation of CL in the final covariate model was as follows: CLi = 9.23× (1 + 0.0005× (θCrCL‐105.78)) × (1 + 0.0017× (θWT‐16)) × eηcl,i (L/h), IF (θDEX) CLi = 1.19× CLi (L/h). The estimation accuracy of all pharmacokinetic parameters were acceptable (relative standard error < 14.74%). The goodness‐of‐fit diagram and bootstrap tests indicated that the final PPK model was stable with acceptable predictive ability. The PPK model may be useful for determining personalized medication levels in pediatric medulloblastoma patients undergoing HD‐MTX therapy. [ABSTRACT FROM AUTHOR]

The theoretical design and the first experimental verification of an exterior dc invisibility cloak that can hide an object from dc detection at a distance are presented. Based on the transformation optics theory, the exterior dc cloak requires negative conductivity material to create folded geometry, which will cancel the real geometry of detected object in distance and make it invisible. Negative conductivities are designed and realized using active devices, together with resistor networks, to generate the equivalent conductivity materials required by the exterior dc cloak. An experimental sample of the dc cloak is fabricated on the printed circuit board and the measured result has excellent agreement with numerical and circuit simulations, showing very good cloaking performance at a distance. [ABSTRACT FROM AUTHOR]

The cover image is based on the Original Article* I Population Pharmacokinetics of High-Dose Methotrexate in Chinese Pediatric Patients with Medulloblastoma i by Dan Yan** et al., https://doi.org/10.1002/bdd.2221.*** GLO:O7I/01mar20:bdd2225-toc-0001.jpg PHOTO (COLOR): . gl. [Extracted from the article]

The work functions of LnB6 (Ln = Pr, Nd, and Gd) at (100) plane are systematically studied by first‐principles calculation based on density functional theory. It reveals that the work function of LnB6 at (100) plane obeys the relation of Φ(PrB6) < Φ(NdB6) < Φ(GdB6). The high‐quality CexLayPryNd0.05Gd0.05B6 (x = 0.5, y = 0.2 or x = 0.6, y = 0.15 or x = 0.7, y = 0.1) single crystals are successfully prepared by the optical float‐zone technique. The crystal quality and emission properties of single crystals are characterized by rotating target X‐ray diffraction, X‐ray single‐crystal diffraction, X‐ray Laue diffraction, and the thermal electron emission measurements. The results present that the as‐grown single crystals are of high quality and lower work function than single crystal CeB6. The maximum emission current density of 60.69 A cm−2 obtained at 1873 K under the applied voltage of 4000 V belongs to the Ce0.5La0.2Pr0.2Nd0.05Gd0.05B6 single crystal with (100) surface. The preparation, crystalline qualities, and thermionic emission properties of single crystal CexLayPryNd0.05Gd0.05B6 (x = 0.5, y = 0.2 or x = 0.6, y = 0.15 or x = 0.7, y = 0.1) are reported. The optimized emission properties of Jmax = 60.69 A cm−2 and Ф = 2.62 eV for Ce0.5La0.2Pr0.2Nd0.05Gd0.05B6 single crystal are superior over CeB6 single crystal. It is proved doping rare earth elements can reduce the work function and enhance the thermionic emission performance. [ABSTRACT FROM AUTHOR]

Polymer gel is widely used for well temporary plugging in petroleum engineering. This paper researched on a novel environmental and strength‐enhanced composite gel plug prepared by the nanosilica, the polymer hydrolyzed polyacrylamide and environmental friendly crosslinker polyethyleneimine, and the effect of strength enhancement and thermal stability mechanism of the nanosilica in this system was investigated. The experiments results showed that with the increase of the nanosilica concentration, the elastic modulus and viscous modulus, the stress under the same strain and the gel decompose temperature both increased. For the system containing 8% nanosilica, the elastic modulus is about 14 times than the one without it, whereas the viscous modulus is only 70.98 Pa, which is favorable for lowering the absorption damage to the formation. The strain–stress experiment results showed that to reach 45% strain, the stress of 44.6 KPa needed to be loaded (for composite gel with 8 wt% nanosilica) and during the compress process, the gel deformed with no break and after the stress was released, it got back to the original shape soon, indicating its good mechanical and elasticity performance. The differential scanning calorimetry (DSC) results revealed that the after adding nanosilica, more free water can be kept so that the system's thermal stability was effectively improved. The scanning electron microscopic images displayed that the nanosilica particles closely adhere to the polymer network; thus, the 3D structure of the composite gel became more compact and the gel's strength was improved. In the last section, some recommendations for well temporary plugging are proposed. [ABSTRACT FROM AUTHOR]