Search

An understanding of the correlation between maternal immunity and congenital cytomegalovirus (CMV) infection is critical for informing the design and evaluation of an effective maternal vaccine. This study aimed to quantitatively measure the protective effect of pre-existing maternal immunity against congenital CMV (cCMV) infection.A mother-child cohort study was conducted in three maternal and child health hospitals in China from 2015 to 2018. Pregnant women were consecutively enrolled, and anti-CMV pp150 IgG concentration at early, middle and late gestational ages were evaluated. Their newborns were screened for cCMV infection by CMV-DNA testing of saliva and urine.In total, 6729 pregnant women were enrolled, and 6602 of them (98·11%) were positive for CMV IgG at their early gestational age visit (median time: 13 gestational weeks (GW); time range: 6-25 GW). In total, 6228 live newborns were born to seropositive mothers, and 48 (0·77%) of these infants were diagnosed with cCMV infection. The geometric mean concentration (GMC) of CMV IgG at an early gestational age in the women who delivered cCMV-positive newborns (i.e., the transmitters) was 8·54 IU/mL; this was significantly lower than the GMC in the non-transmitters (11·01 IU/mL; P=0·04). In early gestation, the risk of cCMV infection decreased as maternal IgG antibody levels increased (P=0·020); however, the same was not true in middle or late gestation (P0·05). Using receiver operating characteristic analysis, a CMV IgG concentration of 12·83 IU/mL was established as the optimal diagnostic threshold. Compared to lower levels of CMV IgG (12·83 IU/mL) in seropositive pregnant women, higher maternal CMV IgG levels (≥12·83 IU/mL) were associated with a 50% reduction in cCMV infection risk in infants (relative risk=0·50; 95% confidence interval: 0·27-0·93; P=0·028).For seropositive women, a higher level of CMV IgG at an early gestational age is associated with a lower risk of cCMV infection in their newborns.National Natural Science Foundation of China; Science and Technology Key Project in Fujian Province; Merck SharpDohme Corp., Kenilworth, NJ, USA; Fieldwork Funds for graduate students of Xiamen University.

The effects of structural damping to the responses of the vortex-induced vibration of solar tower should be investigated carefully to provide a reference for the structural designers. A new type of elastic test model for a 243-meter-high solar tower is particularly designed and manufactured. A core beam is designed in the test model to simulate the stiffness of the concrete structure, and a coat with baseplate (like a cup) is designed to simulate the steel structure. A structural damping ratio as low as 0.3% is realized, and four level of structural damping ratio, including 0.7%, 1.0%, 1.5% and 2.0%, can be conveniently achieved. A series wind tunnel tests are carried out to investigate the features of the wind-induced responses of the solar tower at the structural damping level of 0.3%, 0.7%, 1.0%, 1.5% and 2.0%. The results show that obvious vortex-induced vibration could be found within wind velocity range of U10 = 21.5–28.4 m/s for the structural damping ratio of 0.7%. At this time, the highest vortex-induced responses (at the wind velocity of U10 = 23.2 m/s), including acceleration at the top, base shear and base moment, are far larger than those at the design wind velocity (U10 = 41.0 m/s). Moreover, it appears that the wind-induced responses in cross-wind direction are far higher than those in the along-wind direction. The most important point is that the base shear and moment in the cross-wind direction measured from wind tunnel tests are far higher than the values obtained from the Code ACI 307–08. The wind-induced responses of the solar tower are extremely sensitive to the structural damping of the test model. For example, the highest acceleration, base shear and moment in cross-wind direction are respectively reduced by about 67%, 74%, 71% when structural damping ratio slightly increases from 0.7% to 1.0%. It seems that the vortex-induced vibration of the solar tower could be effectively mitigated if the structural damping ratio could be enhanced over 1.0%.

A self-sustained, complete and miniaturized methanol fuel processor has been developed based on modular integration and microreactor technology. The fuel processor is comprised of one methanol oxidative reformer, one methanol combustor and one two-stage CO preferential oxidation unit. Microchannel heat exchanger is employed to recover heat from hot stream, miniaturize system size and thus achieve high energy utilization efficiency. By optimized thermal management and proper operation parameter control, the fuel processor can start up in 10 min at room temperature without external heating. A self-sustained state is achieved with H 2 production rate of 0.99 Nm 3 h −1 and extremely low CO content below 25 ppm. This amount of H 2 is sufficient to supply a 1 kW e proton exchange membrane fuel cell. The corresponding thermal efficiency of whole processor is higher than 86%. The size and weight of the assembled reactors integrated with microchannel heat exchangers are 1.4 L and 5.3 kg, respectively, demonstrating a very compact construction of the fuel processor.

The interplay between Hsf4 and Hsf1 plays an important role in the regulation of lens homeostasis. However, the mechanism of the intermolecular association involved is still unclear. In this paper, we find that reconstitution of Hsf4b into Hsf4−/− lens epithelial (mLEC/Hsf4−/−) cells can simultaneously downregulate Hsp70 expression and upregulate the expression of small heat shock proteins Hsp25 and αB-crystallin at both RNA and protein levels. ChIP assay results indicate Hsf4b, which binds to the promoters of Hsp90α, Hsp70.3, Hsp25 and αB-crystallin but not Hsp70.1, can inhibit Hsf1 binding to Hsp70.3 promoter and the heat shock mediated Hsp70 promoter activity by reducing Hsf1 protein expression. Hsf4b N-terminal hydrophobic region can interact with Hsf1 N-terminal hydrophobic region. Their interaction impairs Hsf1's intramolecular interaction between the N- and C-terminal hydrophobic regions, leading to Hsf1's cytosolic retention and protein degradation. Both lysosome inhibitors (chloroquine, pepstatin A plus E64d) and proteasome inhibitor MG132 can inhibit Hsf4-mediated Hsf1 protein degradation, but MG132 can induce Hsf1 activation as well. Upregulation of Hsf4b can significantly inhibit cisplatin and staurosporine induced lens epithelial cell apoptosis through direct upregulation of Hsp25 and αB-crystallin expression. Taken together, our results imply that upregulation of Hsf4b modulates the expression pattern of heat shock proteins in lens tissue by either directly binding to their promoters or promoting Hsf1 protein degradation. Moreover, upregulation of Hsf4b protects lens cell survival by upregulating anti-apoptotic pathways. These studies reveal a novel regulatory mechanism between Hsf1 and Hsf4b in modulating lens epithelial cell homeostasis.

Tumor necrosis factor-related apoptosis-inducing ligand can induce apoptosis in many tumor cell lines. This apoptotic effect is mediated by interaction of TRAIL and its receptors, which include Death Receptor 4 (DR4) and Death Receptor 5 (DR5). Some antibodies to DR4 or DR5 do not have anti-tumor ability without cross-linking but exhibit anti-tumor ability in the presence of a cross-linking reagent. Here, we suggest that the tetravalent anti-DR5 antibody can induce apoptosis of cancer cells independent of cross-linking reagent. The single-chain variable fragment of the anti-DR5 antibody, HSA (human serum albumin) – p53 gene, comprising residues 490–513 of HSA and the tetramerization domain of human p53 were assembled into the tetravalent antibody by an overlapping PCR. Results of size exclusion HPLC indicated that the purified protein exhibited a major peak (tetramer) and a minor peak (dimer). MTT assay demonstrated the tetravalent antibody without cross-linking could inhibit survival of Jurkat and EC9706 cells in a dose-dependent manner while the monovalent antibody could not inhibit survival of Jurkat and EC9706 cells. IC50 of Jurkat cell was 3.2 mg/L and IC50 of EC9706 cell was 3.9 mg/L. Furthermore, the Annexin V/PI assay and the Hoechst 33258 staining showed that the tetravalent antibody could efficiently induce apoptosis of Jurkat and EC9706 cells. Therefore, the tetravalent anti-DR5 antibody can act as a direct agonistic antibody, and initiate efficient apoptotic independent of cross-linking reagent. Thus, the tetravalent anti-DR5 antibody will be a new kind of candidate for potential cancer therapeutics.

Hsf4b, a key regulator of postnatal lens development, is subjected to posttranslational modifications including phosphorylation. However, the phosphorylation sites in Hsf4b and their biological effects on the transcription activity of Hsf4b are poorly understood. Here we examined 17 potential phosphorylation residues in Hsf4b with alanine-scanning assays and found that a T472A mutation diminished Hsf4b-mediated expression of Hsp25 and alphaB-crystallin. In contrast, the phosphomimetic mutation of T472D enhanced their expression. Further investigation demonstrated that Hsf4b could interact with nuclear-transporter importin beta-1 and Hsc70 via amino acids 246-320 and 320-493, respectively. T472A mutation reduced Hsf4bs interaction with importin beta-1, while enhancing its interaction with Hsc7O, resulting in Hsf4b cytosolic re-localization, protein instability and transcription activity attenuation. At the upstream, MEK6 was found to interact with Hsf4b and enhance Hsf4b's nuclear translocation and transcription activity, probably by phosphorylation at sites such as T472. Taken together, our results suggest that phosphotylation of Hsf4b at T472 by protein kinases such as MEI(6 regulates Hsf4b interaction with the importin V I -Hsc7O complex, resulting in blockade of its nuclear translocation and transcriptional activity of Hsf4b.

Mercapto-silica (SiO2-SH) microspheres were prepared via direct hydrolysis of 3-mercaptopropyltrimethoxysilane (MPS) in a basic aqueous solution. The content of surface thiol group (SH) of SiO2-SH microspheres was measured by Ellman's reagent method and X-ray photoelectron spectroscopy (XPS) and the content of surface thiol group of SiO2-SH microspheres is strongly dependent on the reaction conditions. The thermal stability of SiO2-SH microspheres was evaluated by thermogravimetric (TG) analysis, which tended to reduce with the increase of content of surface thiol groups. SiO2-SH microspheres can be easily modified with reduced glutathione (GSH) to generate SiO2-GSH microspheres for the affinity separation of Glutathione S-transferase (GST). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed to examine the validity of the separation procedure. The results showed that SiO2-GSH microspheres were efficient in GST affinity separation from mixed proteins.

The dimethyl ether steam reforming (DME SR) was carried out over the composite catalyst of ZnO–Cr 2 O 3 coupled with Al 2 O 3 , TiO 2 or TiO 2 –Al 2 O 3 in the microreactor. The results showed that the catalytic activities were greatly enhanced over the composite catalyst of ZnO–Cr 2 O 3 combined with TiO 2 –Al 2 O 3 (ZnCr–TiAl) in comparison to those combined with Al 2 O 3 or TiO 2 in DME SR. By evaluating the catalytic activity of solid acids in DME hydrolysis, it was proposed that the better performance of TiO 2 –Al 2 O 3 in DME hydrolysis contributed to the superior activity of ZnCr–TiAl in DME SR, indicating a higher DME hydrolysis activity favored DME SR. In view of the characterization of N 2 physisorption, scanning electron microscope, X-ray diffraction and NH 3 temperature-programmed desorption, the promotion effect of TiO 2 on both DME hydrolysis and steam reforming was discussed in terms of the modification effect of TiO 2 on the acid properties of Al 2 O 3 surface. The acid strength or total acid amount was enhanced by the addition of different TiO 2 content. In the 150 h medium stability test, there was no obvious deactivation for ZnCr–TiAl catalyst with the H 2 production rate of 345 mol h − 1 k g cat − 1 and the CO selectivity in the dry reformate remained below 6%. The characterization results of the used catalyst revealed that no change in the crystalline phase and size occurred on the spent catalyst.

A series of ZnO–Al2O3 catalysts with various ZnO/(ZnO + Al2O3) molar ratios have been developed for hydrogen production by dimethyl ether (DME) steam reforming within microchannel reactor. The catalysts were characterized by N2 adsorption-desorption, X-ray diffraction and temperature programmed desorption of NH3. It was found that the catalytic activity was strongly dependent on the catalyst composition. The overall DME reforming rate was maximized over the catalyst with ZnO/(ZnO + Al2O3) molar ratio of 0.4, and the highest H2 space time yield was 315 mol h−1·kgcat−1 at 460 °C. A bi-functional mechanism involving catalytic active site coupling has been proposed to account for the phenomena observed. An optimized bi-functional DME reforming catalyst should accommodate the acid sites and methanol steam reforming sites with a proper balance to promote DME steam reforming, whereas all undesired reactions should be impeded without sacrificing activity. This work suggests that an appropriate catalyst composition is mandatory for preparing good-performance and inexpensive ZnO–Al2O3 catalysts for the sustainable conversion of DME into H2-rich reformate.

In this study, a series of ZnO-Al2O3 catalysts with various ZnO/(ZnO + Al2O3) molar ratios have been evaluated for the high-temperature steam reforming of methanol, and the optimizing catalyst composition consists in the range of 0.50-0.67. The catalysts were characterized by N-2 adsorption-desorption, X-ray diffraction and UV-vis spectra. In the case of ZnO/(ZnO + Al2O3)> 0.5, a significant proportion of Zn could dissolve in ZnAl2O4, resulting in Zn-rich non-stoichiometric spine!, in which the Zn2+ ions located both at the tetrahedral and octahedral sites. It was noticed that such a coordination of Zn2+ ions in the octahedral position brought about a higher CO selectivity. Further investigation illuminated water gas shift and methanol decomposition reaction were both involved in the formation of CO. There was no noticeable deactivation for ZnO-Al2O3 with the ZnO/(ZnO+ Al2O3) molar ratio of 0.50 during the 200h continuous operation (GHSV= 17930 h(-1), T=420 degrees C). The H-2 space time yield is 55 Lh(-1)g(cat)(-1) and the concentration of CO in the dry gaseous products was lower than 0.8%. (C) 2010 Elsevier B.V. All rights reserved.

Heat shock factor 4 (Hsf4b) has been identified as a novel cataractogenic protein whose mutation has been closely associated with hereditary cataracts in humans and animals. It acts both as a transcription activator and a transcription inhibitor in the regulation of its downstream targets during lens development. However, the signaling factors that regulate Hsf4b transcription activity are still not completely defined. Here, we found that Hsf4b, not Hsf4a (another isoform of Hsf4), acts as the inhibitor of CMV promoter as well as the activator of Hsp25 in the Hsf4-/- mouse lens epithelial cell line (mLEC/hsf4-/-). Hsf4b inhibits CMV-promoter activity by directly binding to TTCC (HSE motif) at 173-176bps in the CMV promoter. The phosphorylation of Hsf4b/S299 in the PDSM motif, which is absent in Hsf4a, participates in the negative regulation of the CMV promoter. The transcriptional inhibition of Hsf4b is associated with transcriptional inhibitor Daxx. Hsf4b can interact and co-localize with Daxx in the nucleus, and their association is regulated by the phosphorylation of Hsf4b/S299. In addition, we found that Hsf4a and Hsf1 were also associated with Daxx. However, in contrast to activating Hsf1, Daxx can repress Hsf4b-induced expression of Hsp25 in the mLEC/hsf4-/- cell line. Our results demonstrate that the transcription-inhibitory function of Hsf4b is regulated by the phosphorylation of Hsf4b/S299 and phosphorylation-dependent association with Daxx.

T-type microchannel reactors were used to prepare monodispersed nanocrystals of barium sulfate and boehmite. The size of barium sulfate is strongly dependent on the velocity of the reactants in the channel. High velocity is beneficial for producing small particles. The concentration of reactants also affects the size. Boehmite was prepared by neutralization of NaAlO2 and Al2(SO4)3. Changing the proportion of NaAlO2 and Al2(SO4)3 will lead to different pH values which determine the phase of alumina. High efficiency of micromixing is the key factor of the purity of the alumina morphology. Na2CO3 was used to adjust pH at given value during aging process. Aging is indispensable for the amorphous alumina to crystallize to boehmite. Raising the age temperature would reduce the time the crystallization need. The morphology and purity were characterized by powder X-ray diffraction (XRD) and transmission electron microscopy (TEM).

Ethylene is essential material for the petrochemical industry. Ethylene production via catalytic dehydration of ethanol over TiO2/-gamma-Al2O3 catalysts in multi-microchannel reactors is reported in this paper. The physicochernical properties of these catalysts are characterized by X-ray diffraction (XRD) and FT-IR spectrum. The effects of operation parameters, such as ethanol concentration, reaction temperature and liquid hourly space velocity, have been investigated experimentally. The reaction results indicate that the catalysts doped with TiO2 have high ethanol conversion of 99.96% and ethylene selectivity of 99.4%. Ethylene yield of 26 g/(g(cat) h) can be achieved, which provides very favorable foundation for the process intensification and miniaturization of the ethylene production process using bioethanol. (c) 2007 Elsevier B.V. All rights reserved.

Catalysts with a high activity and a high stability play an important role in the process of hydrogen generationvia methanol oxidation reforming for PEM fuel cell. In this paper, catalysts with high activities and selectivities for methanol oxidation reforming have been developed. The reaction experimental results indicate that a ZnO-Cr2O3/CeO2-ZrO2/Al2O3 ceramic monolithic catalyst is a promising catalyst for the hydrogen production from methanol oxidation reforming. There was no significant deactivation of the catalyst over 1000 h of continuous operation and the CO concentration in thereformate effluent dry gas wasless than1.4%,and methaneproduced was negligible under the molar ratiosof O2/MeOH = 0.3, H2O/MeOH = 1.2, and gas hourly space velocity equal to 3850 h � 1 .

Methanol oxidation reforming is an important reaction in the process of hydrogen generation for PEMFC. In this paper, we report the wall coated catalysts in a microchannel reactor for methanol oxidation reforming. The preparation method of the wall coating catalyst was studied in detail, i.e., the sol–gel and solution-coating techniques. To prepare the catalysts for methanol oxidation reforming, the washing-coating layer of CuZnAl was prepared by the sol–gel technique, and then the active layer was coated on it by solution-coating technique with emulsion colloid containing Pd–ZnO particles. Both the supporting layer and catalyst on the stainless steel foils were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The formed wash-coating layer with ordered arrays of petaloid microcrystallites in layer surface and Pd–Zn alloy crystal phase can be clearly observed. The reaction experimental results indicated that the catalyst prepared have high activity and relatively high stability. # 2006 Elsevier B.V. All rights reserved.

This study showed that a ZnO-Cr2O3/CeO2-ZrO2/Al2O3 (Zn-Cr) catalyst was a promising catalyst for hydrogen production from methanol due to its high stability and selectivity. There was no significant deactivation of the catalyst over 300 min of continuous operation when water was introduced into the feed. In the absence of water, the catalyst deactivated rapidly due to coke formation. The addition of water into the feed changed the route of methanol conversion and improved its rate. In order to investigate the pathway of CO formation. three reactions, i.e. decomposition of methanol (DM), steam reforming of methanol (SRM) and water gas-shift (WGS), were studied in this paper. The results showed that CO and CO2 were produced through the DM reaction and SRM reaction, respectively. The WGS and reverse WGS reactions were negligible. Adding H, and CO in the feed did not influence the process behavior of the SRM reaction. The addition of CO2 and H2O into the feed decreased the yield Of CO2. (c) 2006 Elsevier B.V. All rights reserved.

It is indispensable to remove CO at the level of less than 50 ppm in H2-rich feed gas for the proton exchange membrane (PEM) fuel cells. In this paper, catalyst with high activity and selectivity, and a microchannel reactor for CO preferential oxidation (PROX) have been developed. The results indicated that potassium on supported Rh metal catalysts had a promoting effect in the CO selective catalytic oxidation under H2-rich stream, and microchannel reactor has an excellent ability to use in on-board hydrogen generation system. CO conversion keeps at high levels even at a very high GHSV as 500 000 h −1 , so, miniaturization of hydrogen generation system can be achieved by using the microchannel reactor.

Vectors derived from human immunodeficiency virus (HIV) hold promise for efficient gene delivery into human hematopoietic cells. In this study, HIV vectors containing different combinations of cis-acting elements, including the HIV central flap sequence, and the woodchuck posttranscriptional regulatory element (WPRE) in combination with two different promoters, were used to transduce primary human lymphocytes and cord blood CD34+ progenitor cells. The effect of these elements on the transduction efficiency and transgene expression was systematically evaluated. The results demonstrate that with the combination of flap, WPRE sequences, and the promoter derived from spleen focus-forming virus (SFFV), a foreign gene can be efficiently delivered into primary human T lymphocytes and cord blood CD34+ cells. The study establishes the parameters for proper vector design to efficiently deliver foreign genes into human hematopoietic cells.