The infinite-layer nickelates,proposed as analogs to superconducting cuprates,provide a promising platform for exploring the mechanisms of unconventional superconductivity.However,the superconductivity has been exclus...The infinite-layer nickelates,proposed as analogs to superconducting cuprates,provide a promising platform for exploring the mechanisms of unconventional superconductivity.However,the superconductivity has been exclusively observed in thin films under atmospheric pressure,underscoring the critical role of the heterointerface.展开更多
In recent years,the development of ultrafast transmission electron microscopy(UTEM)has created new opportunities for studying dynamic processes at the nanoscale with unprecedented temporal resolution.~([1–3])The sign...In recent years,the development of ultrafast transmission electron microscopy(UTEM)has created new opportunities for studying dynamic processes at the nanoscale with unprecedented temporal resolution.~([1–3])The significant advances in femtosecond and even attosecond temporal resolution are achieved through the integration of the pump-probe principle with transmission electron microscopy(TEM).展开更多
Combined multimodal nonlinear optical (NLO) microscopies were used to detect and quantify morphological changes associated with stroma and epithelial transformation in colon cancer. Our findings provide complementary ...Combined multimodal nonlinear optical (NLO) microscopies were used to detect and quantify morphological changes associated with stroma and epithelial transformation in colon cancer. Our findings provide complementary information about tissue microstructure, displaying distinctive patterns between normal and malignant human colon. Additionally, we have demonstrated the usefulness of using fixed tissues for the disease diagnostic and prognostic.?The present work provides a framework for using NLO techniques as a clinical diagnostic tool for human colon cancer. NLO metrics could be applied to other disorders, which are characterized by abnormal cell proliferation and collagen assembly.展开更多
Rapid technological advancements drive miniaturization and high energy density in devices,thereby increasing nanoscale thermal management demands and urging development of higher spatial resolution technologies for th...Rapid technological advancements drive miniaturization and high energy density in devices,thereby increasing nanoscale thermal management demands and urging development of higher spatial resolution technologies for thermal imaging and transport research.Here,we introduce an approach to measure nanoscale thermal resistance using in situ inelastic scanning transmission electron microscopy.By constructing unidirectional heating flux with controlled temperature gradients and analyzing electron energy-loss/gain signals under optimized acquisition conditions,nanometer-resolution in mapping phonon apparent temperature is achieved.Thus,interfacial thermal resistance is determined by calculating the ratio of interfacial temperature difference to bulk temperature gradient.This methodology enables direct measurement of thermal transport properties for atomic-scale structural features(e.g.,defects and heterointerfaces),resolving critical structure-performance relationships,providing a useful tool for investigating thermal phenomena at the(sub-)nanoscale.展开更多
SrRuO_(3)is a canonical itinerant ferromagnet,yet its properties in the extreme two-dimensional limit on a(111)crystal plane remain largely unexplored.Here,we demonstrate a complete transformation of its ground state ...SrRuO_(3)is a canonical itinerant ferromagnet,yet its properties in the extreme two-dimensional limit on a(111)crystal plane remain largely unexplored.Here,we demonstrate a complete transformation of its ground state driven by dimensional reduction.As the thickness of(111)-oriented SrRuO_(3)films is reduced to a few unit cells,the system transitions from a metallic ferromagnet to a semiconducting antiferromagnet.This emergent antiferromagnetism is evidenced by a vanishing magnetic remanence and most strikingly,by the appearance of an unconventional twelve-fold anisotropic magnetoresistance.First-principles calculations confirm that an A-type antiferromagnetic order is the stable ground state in the ultrathin limit.Our findings establish(111)dimensional engineering as a powerful route to manipulate correlated electron states and uncover novel functionalities for antiferromagnetic spintronics.展开更多
Nanoscale defects such as dislocations have a significant impact on the phonon thermal transport properties in non-metallic materials.To unravel these effects,an understanding of defect phonon modes is essential.Herei...Nanoscale defects such as dislocations have a significant impact on the phonon thermal transport properties in non-metallic materials.To unravel these effects,an understanding of defect phonon modes is essential.Herein,at the atomic scale,the localized phonons of individual dislocations at a Si/Ge interface are measured via monochromated electron energy loss spectroscopy in a scanning transmission electron microscope.These modes are then correlated with the local microstructure,further revealing the dislocation effects on the local thermal transport properties.The dislocation causes a phonon redshift of several milli-electron-volts within about two to four nanometers of the core,where both the strain field and Ge segregation play roles.With the presence of dislocation,the local interfacial thermal conductance can be either enhanced or reduced,depending on the complex interaction and competition between lattice disorder(dislocation)and element disorder(heterointerface mixing and Ge-segregation)at the interface.These findings provide valuable insights to improve the thermal properties of thermoelectric generators and thermal management systems through proper defect engineering.展开更多
Topochemical fluorination introduces significant structural distortions and emerging properties in perovskite oxides via substituting oxygen with fluorine.However,the rapid fluorination process and the similarity betw...Topochemical fluorination introduces significant structural distortions and emerging properties in perovskite oxides via substituting oxygen with fluorine.However,the rapid fluorination process and the similarity between F and O render the O/F site occupation and local lattice evolution during fluorination unclear.Here we investigated the atomic-scale O/F exchange in La2CoO4and quantified the lattice distortion of three ordered structures:La_(2)CoO_(3.5)F,La_(2)CoO_(3)F_(2),and La_(2)CoO_(2.5)F_(3)by utilizing aberration-corrected electron microscopy.Atomic-resolved elemental mapping provides direct evidence for the O/F occupancy in interstitial and apical sites.We revealed that apical F ions induce significant octahedral tilting from 178°to 165°,linearly proportional to the occupancy rate;and cause the obvious change in the fine structure O K edge,meanwhile apical O is exchanged into interstitial sites.The strong octahedral tilt leads to the in-plane elongation of the[CoO_(4)F_(2)]octahedra.These findings elucidate the atomic-scale mechanisms of the entire fluorination process and highlight the significant role of F in tuning the octahedral tilt of functional oxides.展开更多
Precipitation at grain boundaries is typically not regarded as an efficient method for strengthening materials since it can induce grain boundary embrittlement, which detrimentally affects ductility. In this research,...Precipitation at grain boundaries is typically not regarded as an efficient method for strengthening materials since it can induce grain boundary embrittlement, which detrimentally affects ductility. In this research, we developed a multi-principal element alloy (MPEA) with the composition Cr_(30)Co_(30)Ni_(30)Al_(5)Ti_(5) (at.%), incorporating both intragranular and intergranular nanoprecipitates. Utilizing multiscale, three-dimensional, and in-situ electron microscopy techniques, coupled with computational simulations, we established that intergranular nanoprecipitation in this material plays a crucial role in enhancing strength and promoting dislocation plasticity. The structure of intergranular nanoprecipitation comprises multiple phases with varying composition and structure. Despite the diversity, the crystal planes conducive to the easy glide of dislocations are well-matched, allowing for the sustained continuity of dislocation slipping across different phase structures. Simultaneously, this structure generates an undulated stress field near grain boundaries, amplifying the strengthening effect and facilitating multiple slip and cross-slip during deformation. Consequently, it promotes the proliferation and storage of dislocations. As a result, our material exhibits a yield strength of approximately 1010 MPa and an ultimate tensile strength of around 1500 MPa, accompanied by a significant fracture elongation of 41 %. Our findings illuminate the potential for harnessing intergranular nanoprecipitation to optimize the strength-ductility trade-off in MPEAs, emphasizing the strategy of leveraging complex compositions for the design of sophisticated functional microstructures.展开更多
Adding alloying elements to improve the performances or the manufacturing processes of Al-Mg-Si alloys has long been a serious issue in developing advanced automotive aluminum materials.The Zn element,among those prom...Adding alloying elements to improve the performances or the manufacturing processes of Al-Mg-Si alloys has long been a serious issue in developing advanced automotive aluminum materials.The Zn element,among those promising ones,has demonstrated positive alloying effects on Al-Mg-Si alloys.However,the atomic-scale roles of Zn in an age-hardened Al-Mg-Si-Zn alloy have not been adequately understood.Using atomic-resolution electron microscopy,here we report the precise locations of Zn elements in all hardening precipitates involved and their alloying mechanism at the atomic scale when alloying the alloy.Our results show that Zn atoms enter all the major hardening phases to occupy specific featured atomic sites of the original elements,e.g.the Si1 and Mg2 sites in theβ’-2 phase,and modify their crystal structures,interfacial structures and morphologies in characteristic manners.It is revealed that for theβ’-phase,Zn atoms occupy unique atomic sites,whereas for other phases,they demonstrate similar behaviors as other additive alloying elements such as Ag and Cu do.展开更多
Developing high-efficiency,stable and non-precious electrocatalysts for oxygen reduction reaction(ORR)is highly important for energy conversion and storage.Single atom catalysts(SACs)show good potential in enhancing O...Developing high-efficiency,stable and non-precious electrocatalysts for oxygen reduction reaction(ORR)is highly important for energy conversion and storage.Single atom catalysts(SACs)show good potential in enhancing ORR,however,the specifical control over the coordination surroundings around single metal center to intrinsically modify the electron structure is still a great challenge.Herein,we demonstrate that a 3 D hybrid MOF composed of cobalt doped ZIF-L and ZIF-8,featuring star morphology with six equal branches,can be used as an advanced precursor for making the Co SACs for greatly boosted ORR.The as-synthesized Co_(SA)-N-C exhibits excellent ORR activity with E_(1/2) of 0.891 V in alkaline medium,outperforming the commercial Pt/C by 39 m V.Moreover,the E_(1/2) of Co_(SA)-N-C(0.790 V)is merely 15 m V,less than that of Pt/C(0.805 V)in acid medium,which is among the best in the reported state-of-the-art SACs.DFT calculations demonstrate that the enhanced ORR performance is assigned to the formation of atomically isolated cobalt atom coordinated three N atoms and one C atom,which is easier to decrease the free energy of rate determining step and accelerate the ORR process than that of traditional cobalt atom coordinated four N atoms.In addition,a primary Zn-air battery with Co_(SA)-N-C cathode reveals a maximum power density of 92.2 m W cm^(-2) at 120.0 m A cm^(-2),far higher than that of commercial catalysts(74.2 m W cm^(-2) at 110.0 m A cm^(-2)).展开更多
BACKGROUND： Structural and functional synaptic changes, as well as blood-brain barrier （BBB） changes, affect the micro-environment of nervous tissue and excitation, both of which play an important role in epilepsy....BACKGROUND： Structural and functional synaptic changes, as well as blood-brain barrier （BBB） changes, affect the micro-environment of nervous tissue and excitation, both of which play an important role in epilepsy. OBJECTIVE： To observe synaptic and BBB ultrastructural changes in the motor cortex of a rat epilepsy model induced by coriaria lacton, and to investigate the synaptic and BBB effects on the mechanism of epilepsy. DESIGN： A randomized controlled animal experiment. SETTING： Department of Histology and Embryology, Luzhou Medical College; and Electron Microscopy Laboratory, Luzhou Medical College. MATERIALS： Twenty healthy male Sprague Dawley rats, aged 8 weeks, were chosen for this study. The rats weighed （280 ± 50） g and were supplied by the Experimental Animal Center of Luzhou Medical College. Experimentation was performed in accordance with the ethical guidelines for the use and care of animals. The animals were randomly divided into a control group and an epilepsy group, with 10 rats in each group. METHODS： This study was performed at the Department of Histology and Embryology, and Electron Microscopy Laboratory, Luzhou Medical College between February and December 2006. According to the protocol, the epilepsy group was injected with 10 μ L/100 g coriaria lacton into the lateral ventricles to establish an epileptic model. The control group rats were not administered anything. Eight days after the model was established, all rats were anesthetized with ether. The motor cortex was removed and sectioned into ultrathin sections. Synaptic and BBB ultrastructural changes were observed by electron microscopy. MAIN OUTCOME MEASURES： （1）Structural changes of three different parts of the synapses, synaptic cleft width, postsynaptic density thickness, proportion of perforation synapses, curvature of synaptic interface, and length of active zones. （2）Capillary and BBB changes （endothelium, basement membrane, pericyte, and the astrocyte endfeet）. RESULTS： （1）Curvature of synaptic interface, length of active zones, thickness of postsynaptic density, and percentage of perforation synapses increased significantly. （2）There was significant edema in the endothelium, basement membrane, and the pericyte of the epilepsy group; the electron density of the basement membrane was reduced. CONCLUSION： （1） The coriaria lacton treatment altered synaptic ultrastructure, as well as BBB characteristics, in the epileptic rat model, and also improved synaptic transmission efficiency, as well as BBB permeability; （2）Synaptic and BBB ultrastructural changes might play an important role in the mechanism of epilepsy.展开更多
AIM：To examine the expression of intercellular adhesion molecule-1 （ICAM-1） and lymphocyte function-associated antigen-1（LFA-1）expression on canals of Hering （COH）and bile ductules associated with the autoimmun...AIM：To examine the expression of intercellular adhesion molecule-1 （ICAM-1） and lymphocyte function-associated antigen-1（LFA-1）expression on canals of Hering （COH）and bile ductules associated with the autoimmune process of bile duct destruction in primary biliary cirrhosis（PBC）．METHODS：Ten wedged liver biopsies of PBC（five cases each of stages 2 and 3）were studied. The liver specimens were processed for transmission electron microscopy. Immunohistochemistry was performed using anti-ICAM-1 and anti-LFA-1 mouse mAbs.In situ hybridization was done to examine the messenger RNA expression of ICAM-1 in formalin-fixed．paraffin-embedded sections using peptide nucleic acid probes and the catalyzed signal amplification （CSA）technique．Immunogold-silver staining for electron microscopy was Derrormed using anti-ICAM and anti-LFA-1 mouse mAbs．The immunogold particles on epithelial cells of bileductules and cholangiocytes of CoH cells were counted and analyzed semi-quantitatively．Western blotting was performed to confirm ICAM-1 protein expression．RESULTS：In liver tissues of PBC patients．immunohi-stochemistry showed aberrant ICAM-1 expression on the plasma membrane of epithelial cells lining bile ductules，and also on mature cholangiocytes but not on hepatocytes in CoH．LFA-1-positive lymphocytes were closely associated with epithelial cells in bile ductules．ICAM-1 expression at protein level was confirmed by Western blot．In situ hybridization demonstrated ICAM-1 mRNA expression in bile ductules and LFA-1 mRNA in lymphocytes infiltrating the bileductules．By immunoelectron microscopy，ICAM-1 was demonstrated on the basal suface of epithelial cells in bile ductules and on the luminal surfaces of cholangiocytes in damaged COH．Cells with intermediate morphology resembling progenitor cells in Coil were not labeled with ICAM-1 and LFA-1．CONCLUSION：De novo expression of ICAM-1 both on mature cholangiocytes in COH and epithelial cells in bile ductules in PBC implies that lymphocyte-induced destruction through adhesion by ICAM-1 and binding of LFA-1-expressing activated lymphocytes takes place not only in bile ductules but also in the COH．展开更多
Objective:To evaluate the antibacterial activity and neuroprotective capacity of the ethanolic and aqueous extracts of Tarenaya spinosa(T.spinosa)as well as to determine and quantify some of its polyphenols by high pe...Objective:To evaluate the antibacterial activity and neuroprotective capacity of the ethanolic and aqueous extracts of Tarenaya spinosa(T.spinosa)as well as to determine and quantify some of its polyphenols by high performance liquid chromatography with diode-array detection(HPLC-DAD).Methods:The bacterial Escherichia coli,Staphylococcus aureus and Pseudomonas aeruginosa strains,grown in Heart Agar Infusion,were tested.The drugs gentamicin,norfloxacin and imipenem were used to evaluate the modulating or antagonistic capacity of the T.spinosa extracts.The extract was analysed by HPLC-DAD to determine the main phenolic compounds.For the cell viability tests,individual heads of the Nauphoeta cinerea arthropod model were removed,homogenized in Trifluoromethyl ketone and centrifuged afterwards.Subsequently,20μL of NaN O_(2) were added to the biological material,except in the control group,to evaluate the protection capacity of the extracts.The homogenate of the insect heads was incubated for 2 h in tubes containing tetrazolium bromide.Results:HPLC-DAD demonstrated that the ethanolic extract of T.spinosa presented caffeic acid as the major compound.The ethanolic extract also showed neuroprotective effects at concentrations≥10μg/mL,while aqueous extract was shown to have a protective effect only at the concentration of 100μg/mL.The aqueous extract demonstrated a clinically relevant antibacterial activity against the Staphylococcus aureus multidrug resistant strain-MDR,with MIC 512μg/m L.However,when the extracts were associated with gentamicin and imipenem,a synergism was detected against Staphylococcus aureus and Escherichia coli MDR strains.Conclusions:Although it does not present an antibacterial action,the extracts of T.spinosa can be used in the pharmaceutical industries since its extracts show modulating action of drugs.Besides,these natural products have neuroprotective capacity.展开更多
As a newly developed method for fabricating Josephson junctions,a focused helium ion beam has the advantage of producing reliable and reproducible junctions.We fabricated Josephson junctions with a focused helium ion ...As a newly developed method for fabricating Josephson junctions,a focused helium ion beam has the advantage of producing reliable and reproducible junctions.We fabricated Josephson junctions with a focused helium ion beam on our 50 nm YBa_(2)Cu_(3)O_(7-δ)(YBCO)thin films.We focused on the junction with irradiation doses ranging from 100 to 300 ions/nm and demonstrated that the junction barrier can be modulated by the ion dose and that within this dose range,the junctions behave like superconductor–normal conductor–superconductor junctions.The measurements of the I–V characteristics,Fraunhofer diffraction pattern,and Shapiro steps of the junctions clearly show AC and DC Josephson effects.Our findings demonstrate high reproducibility of junction fabrication using a focused helium ion beam and suggest that commercial devices based on this nanotechnology could operate at liquid nitrogen temperatures.展开更多
The presence ofα/αon priorβ/βgrain boundaries directly impacts the final mechanical properties of the titanium alloys.Theβ/βgrain boundary variant selection of titanium alloys has been assumed to be unlikely owi...The presence ofα/αon priorβ/βgrain boundaries directly impacts the final mechanical properties of the titanium alloys.Theβ/βgrain boundary variant selection of titanium alloys has been assumed to be unlikely owing to the high cooling rates in laser powder bed fusion(L-PBF).However,we hypothesize that powder characteristics such as morphology(non-spherical)and particle size(50–120μm)could affect the initial variant selection in L-PBF processed Ti-6Al-4V alloy by locally altering the cooling rates.Despite the high cooling rate found in L-PBF,results showed the presence ofβ/βgrain boundaryαlath growth inside two adjacent priorβgrains.Electron backscatter diffraction micrographs confirmed the presence ofβ/βgrain boundary variant selection,and synchrotron X-ray high-speed imaging observation revealed the role of the“shadowing effect”on the locally decreased cooling rate because of keyhole depth reduction and the consequentβ/βgrain boundaryαlath growth.The self-accommodation mechanism was the main variant selection driving force,and the most abundantα/αboundary variant was type 4(63.26°//[10553¯]).The dominance of Category IIαlath clusters associated with the type 4α/αboundary variant was validated using the phenomenological theory of martensite transformations and analytical calculations,from which the stress needed for theβ→αtransformation was calculated.展开更多
A number of studies have focused on the beneficial properties of Curcumin (diferuloyl methane, used in South Asian cuisine and traditional medicine) such as the chemoprevention of cancer. Recent studies have also indi...A number of studies have focused on the beneficial properties of Curcumin (diferuloyl methane, used in South Asian cuisine and traditional medicine) such as the chemoprevention of cancer. Recent studies have also indicated that this material has significant benefits for the treatment of cancer and is currently undergoing several clinical trials. We have been interested in the application of this compound as a therapeutic agent for advanced prostate cancer, particularly the skeletal complications in this malignancy. Our earlier work indicated that this compound could inhibit the osteomimetic properties which occur in castration resistant prostate cancer cells, by interfering with the common denominators between these cancer cells and the bone cells in the metastatic tumor microenvironment, namely the osteoblasts and the osteoclast. We predicted that curcumin could break the vicious cycle of reciprocal stimulation that results in uncontrolled osteolysis in the bony matrix. In this work, we have evaluated the potential of this compound in inhibiting the bone metastasis of hormone refractory prostate cancer cells in an established animal model. Our results strongly suggest that curcumin modulates the TGF-βsignaling that occurs due to bone matrix degradation by up-regulating the metastasis inhibitory bone morphogenic protein-7 (BMP-7). This enhancement of BMP-7 in the context of TGF-β in the tumor microenvironment is shown to enhance the mesenchymal-to-epithelial transition. Most importantly, we show that as a result of BMP-7 up-regulation, a novel brown/beige adipogenic differentiation program is also up-regulated which plays a role in the inhibition of bone metastasis. Our results suggest that curcumin may subvert the TGF-β signaling to an alternative adipogenic differentiation program in addition to the previously established interference with the osteomimetic properties, thus inhibiting the bone metastatic processes in a chemopreventive as well as therapeutic setting.展开更多
The genetic bases and molecular mechanisms involved in the assembly and function of the flagellum components as well as in the regulation of the flagellar movement are not fully understood, especially in humans. There...The genetic bases and molecular mechanisms involved in the assembly and function of the flagellum components as well as in the regulation of the flagellar movement are not fully understood, especially in humans. There are several causes for sperm immotility, of which some can be avoided and corrected, whereas other are related to genetic defects and deserve full investigation to give a diagnosis to patients. This review was performed after an extensive literature search on the online databases PubMed, ScienceDirect, and Web of Science. Here, we review the involvement of regulatory pathways responsible for sperm motility, indicating possible causes for sperm immotility. These included the calcium pathway, the cAMP-dependent protein kinase pathway, the importance of kinases and phosphatases, the function of reactive oxygen species, and how the regulation of cell volume and osmolarity are also fundamental components. We then discuss main gene defects associated with specific morphological abnormalities. Finally, we slightly discuss some preventive and treatments approaches to avoid development of conditions that are associated with unspecified sperm immotility. We believe that in the near future, with the development of more powerful techniques, the genetic causes of sperm immotility and the regulatory mechanisms of sperm motility will be better understand, thus enabling to perform a full diagnosis and uncover new therapies.展开更多
AIM To evaluate the liver regeneration capacity(LRC) after partial hepatectomy(PH) in experimental non-alcoholic steatohepatitis(NASH).METHODS Fifty-four female rats were fed a high-fat, high-cholesterol diet(HFCD, 65...AIM To evaluate the liver regeneration capacity(LRC) after partial hepatectomy(PH) in experimental non-alcoholic steatohepatitis(NASH).METHODS Fifty-four female rats were fed a high-fat, high-cholesterol diet(HFCD, 65% fat, 1% cholesterol) or standard diet(STD) for 16 wk. A 70% PH was performed and the animals were euthanised before PH or 2 or 5 d postPH. LRC was evaluated using: The total number of Ki-67 positive hepatocytes in the caudate lobe, N(Ki-67, lobe) evaluated in a stereology-based design, the regenerated protein ratio(RPR), prothrombin-proconvertin ratio(PP), and m RNA expression of genes related to regeneration.RESULTS The HFCD NASH model showed significant steatosis with ballooning and inflammation, while no fibrosis was present. Mortality was similar in HFCD and STD animals following PH. HFCD groups were compared to respective STD groups and HFCD animals had a significantly elevated alanine transaminase at baseline(P < 0.001), as well as a significantly elevated bilirubin at day 2 after PH(P < 0.05). HFCD animals had a higher N(Ki-67, lobe) at baseline,(P < 0.0001), day 2 after PH(P = 0.06) and day 5 after PH(P < 0.025). We found no significant difference in RPR or PP neither 2 or 5 d post-PH. Expression of liver regeneration genes(e.g., hepatic growth factor) was higher at both day 2 and 5 post-PH in HFCD groups(P < 0.05).CONCLUSION NASH rats had a preserved LRC after hepatectomy when compared to STD rats. The methods and models of NASH are essential in understanding and evaluating LRC.展开更多
The aim of the present work was to present the outcomes of the patients with Y-chromosome microdeletions treated by intracytoplasmic sperm injection （ICSI）, either using fresh （TESE） or frozen-thawed （TESE-C） te...The aim of the present work was to present the outcomes of the patients with Y-chromosome microdeletions treated by intracytoplasmic sperm injection （ICSI）, either using fresh （TESE） or frozen-thawed （TESE-C） testicular sperm and ejaculated sperm （EJAC）. The originality of this work resides in the comparisons between the different types of Y-microdeletions （AZFa, AZFb, and AZFc） and treatments, with detailed demographic, stimulation, embryological, clinical, and newborn （NB） outcomes. Of 125 patients with Y-microdeletions, 33 patients presented severe oligozoospermia （18 performed ICSI with ejaculated sperm） and 92 secretory azoospermia （65 went for TESE with 40 having successful sperm retrieval and performed ICSI）. There were 51 TESE treatment cycles and 43 TESE-C treatment cycles, with a birth of 19 NB （2 in AZFa/TESE-C, 12 in AZFc/TESE, and 5 in AZFc/TESE-C）. Of the 29 EJAC cycles, there was a birth of 8 NB （in AZFc）. In TESE and EJAC cycles, there were no significant differences in embryological and clinical parameters. In TESE-C cycles, there was a significant lower oocyte maturity rate, embryo cleavage rate and mean number of embryos transferred in AZFb, and a higher mean number of oocytes and lower fertilization rate in AZFc. In conclusion, although patients with AZFc microdeletions presented a high testicular sperm recovery rate and acceptable clinical outcomes, cases with AZFa and AZFb microdeletions presented a poor prognosis. Due to the reported heredity of microdeletions, patients should be informed about the infertile consequences on NB and the possibility of using preimplantation genetic diagnosis for female sex selection.展开更多
Single crystalline ZnSe nanowires with both zincblende and wurtzite structures have been synthesized via a chemical vapour deposition method under different growth conditions. The nanowires are usually 50-80nm in diam...Single crystalline ZnSe nanowires with both zincblende and wurtzite structures have been synthesized via a chemical vapour deposition method under different growth conditions. The nanowires are usually 50-80nm in diameter, and several tens of microns in length. Room-temperature photoluminescence spectra from zincblende and wurtzite ZnSe nanowires show a broad luminescence band peaked at around 2. 71 e V and a deep level emission band peaked at around 2.00 eV, respectively. Effects of post-growth annealing on the photoluminescence of these nanowires have been investigated. Strong room-temperature band-edge emission could be obtained from the annealed zincblende ZnSe nanowires.展开更多
基金supported by the National Natural Science Foundation of China[52125307(to P.G.),12404192(to R.C.S),12274061(to L.Q.)]Key Research and Development Program from the Ministry of Science and Technology(2023YFA1406301)the support from the New Cornerstone Science Foundation through the XPLORER PRIZE。
文摘The infinite-layer nickelates,proposed as analogs to superconducting cuprates,provide a promising platform for exploring the mechanisms of unconventional superconductivity.However,the superconductivity has been exclusively observed in thin films under atmospheric pressure,underscoring the critical role of the heterointerface.
文摘In recent years,the development of ultrafast transmission electron microscopy(UTEM)has created new opportunities for studying dynamic processes at the nanoscale with unprecedented temporal resolution.~([1–3])The significant advances in femtosecond and even attosecond temporal resolution are achieved through the integration of the pump-probe principle with transmission electron microscopy(TEM).
文摘Combined multimodal nonlinear optical (NLO) microscopies were used to detect and quantify morphological changes associated with stroma and epithelial transformation in colon cancer. Our findings provide complementary information about tissue microstructure, displaying distinctive patterns between normal and malignant human colon. Additionally, we have demonstrated the usefulness of using fixed tissues for the disease diagnostic and prognostic.?The present work provides a framework for using NLO techniques as a clinical diagnostic tool for human colon cancer. NLO metrics could be applied to other disorders, which are characterized by abnormal cell proliferation and collagen assembly.
基金supported by the National Natural Science Foundation of China(Grant No.52125307)the National Key R&D Program of China(Grant No.2021YFB3501500)the support from the New Cornerstone Science Foundation through the XPLORER PRIZE。
文摘Rapid technological advancements drive miniaturization and high energy density in devices,thereby increasing nanoscale thermal management demands and urging development of higher spatial resolution technologies for thermal imaging and transport research.Here,we introduce an approach to measure nanoscale thermal resistance using in situ inelastic scanning transmission electron microscopy.By constructing unidirectional heating flux with controlled temperature gradients and analyzing electron energy-loss/gain signals under optimized acquisition conditions,nanometer-resolution in mapping phonon apparent temperature is achieved.Thus,interfacial thermal resistance is determined by calculating the ratio of interfacial temperature difference to bulk temperature gradient.This methodology enables direct measurement of thermal transport properties for atomic-scale structural features(e.g.,defects and heterointerfaces),resolving critical structure-performance relationships,providing a useful tool for investigating thermal phenomena at the(sub-)nanoscale.
基金supported by the National Natural Science Foundation of China(Grant Nos.12204521,12250710675,and 12504198)the National Key R&D Program of China(Grant No.2022YFA1403000)。
文摘SrRuO_(3)is a canonical itinerant ferromagnet,yet its properties in the extreme two-dimensional limit on a(111)crystal plane remain largely unexplored.Here,we demonstrate a complete transformation of its ground state driven by dimensional reduction.As the thickness of(111)-oriented SrRuO_(3)films is reduced to a few unit cells,the system transitions from a metallic ferromagnet to a semiconducting antiferromagnet.This emergent antiferromagnetism is evidenced by a vanishing magnetic remanence and most strikingly,by the appearance of an unconventional twelve-fold anisotropic magnetoresistance.First-principles calculations confirm that an A-type antiferromagnetic order is the stable ground state in the ultrathin limit.Our findings establish(111)dimensional engineering as a powerful route to manipulate correlated electron states and uncover novel functionalities for antiferromagnetic spintronics.
基金supported by the National Natural Science Foundation of China(Grant No.52125307)the National Key R&D Program of China(Grant No.2021YFB3501500)the support from the New Cornerstone Science Foundation through the XPLORER PRIZE。
文摘Nanoscale defects such as dislocations have a significant impact on the phonon thermal transport properties in non-metallic materials.To unravel these effects,an understanding of defect phonon modes is essential.Herein,at the atomic scale,the localized phonons of individual dislocations at a Si/Ge interface are measured via monochromated electron energy loss spectroscopy in a scanning transmission electron microscope.These modes are then correlated with the local microstructure,further revealing the dislocation effects on the local thermal transport properties.The dislocation causes a phonon redshift of several milli-electron-volts within about two to four nanometers of the core,where both the strain field and Ge segregation play roles.With the presence of dislocation,the local interfacial thermal conductance can be either enhanced or reduced,depending on the complex interaction and competition between lattice disorder(dislocation)and element disorder(heterointerface mixing and Ge-segregation)at the interface.These findings provide valuable insights to improve the thermal properties of thermoelectric generators and thermal management systems through proper defect engineering.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.52322212,52025025,5225040212474001)the National Key R&D Program of China(Grant Nos.2022YFA1403203 and 2023YFA1406300)。
文摘Topochemical fluorination introduces significant structural distortions and emerging properties in perovskite oxides via substituting oxygen with fluorine.However,the rapid fluorination process and the similarity between F and O render the O/F site occupation and local lattice evolution during fluorination unclear.Here we investigated the atomic-scale O/F exchange in La2CoO4and quantified the lattice distortion of three ordered structures:La_(2)CoO_(3.5)F,La_(2)CoO_(3)F_(2),and La_(2)CoO_(2.5)F_(3)by utilizing aberration-corrected electron microscopy.Atomic-resolved elemental mapping provides direct evidence for the O/F occupancy in interstitial and apical sites.We revealed that apical F ions induce significant octahedral tilting from 178°to 165°,linearly proportional to the occupancy rate;and cause the obvious change in the fine structure O K edge,meanwhile apical O is exchanged into interstitial sites.The strong octahedral tilt leads to the in-plane elongation of the[CoO_(4)F_(2)]octahedra.These findings elucidate the atomic-scale mechanisms of the entire fluorination process and highlight the significant role of F in tuning the octahedral tilt of functional oxides.
基金supported by the National Science Fund for Distinguished Young Scholars of China(No.52325102)the Natural Science Foundation of Zhejiang Province,China(No.LZ22E010001)the National Key R&D Program of China(No.2023YFB2405802).
文摘Precipitation at grain boundaries is typically not regarded as an efficient method for strengthening materials since it can induce grain boundary embrittlement, which detrimentally affects ductility. In this research, we developed a multi-principal element alloy (MPEA) with the composition Cr_(30)Co_(30)Ni_(30)Al_(5)Ti_(5) (at.%), incorporating both intragranular and intergranular nanoprecipitates. Utilizing multiscale, three-dimensional, and in-situ electron microscopy techniques, coupled with computational simulations, we established that intergranular nanoprecipitation in this material plays a crucial role in enhancing strength and promoting dislocation plasticity. The structure of intergranular nanoprecipitation comprises multiple phases with varying composition and structure. Despite the diversity, the crystal planes conducive to the easy glide of dislocations are well-matched, allowing for the sustained continuity of dislocation slipping across different phase structures. Simultaneously, this structure generates an undulated stress field near grain boundaries, amplifying the strengthening effect and facilitating multiple slip and cross-slip during deformation. Consequently, it promotes the proliferation and storage of dislocations. As a result, our material exhibits a yield strength of approximately 1010 MPa and an ultimate tensile strength of around 1500 MPa, accompanied by a significant fracture elongation of 41 %. Our findings illuminate the potential for harnessing intergranular nanoprecipitation to optimize the strength-ductility trade-off in MPEAs, emphasizing the strategy of leveraging complex compositions for the design of sophisticated functional microstructures.
基金financially supported by the National Key Research and Development Program of China(No.2016YFB0300801)the National Natural Science Foundation of China(Nos.51831004,11427806,51671082,51471067)。
文摘Adding alloying elements to improve the performances or the manufacturing processes of Al-Mg-Si alloys has long been a serious issue in developing advanced automotive aluminum materials.The Zn element,among those promising ones,has demonstrated positive alloying effects on Al-Mg-Si alloys.However,the atomic-scale roles of Zn in an age-hardened Al-Mg-Si-Zn alloy have not been adequately understood.Using atomic-resolution electron microscopy,here we report the precise locations of Zn elements in all hardening precipitates involved and their alloying mechanism at the atomic scale when alloying the alloy.Our results show that Zn atoms enter all the major hardening phases to occupy specific featured atomic sites of the original elements,e.g.the Si1 and Mg2 sites in theβ’-2 phase,and modify their crystal structures,interfacial structures and morphologies in characteristic manners.It is revealed that for theβ’-phase,Zn atoms occupy unique atomic sites,whereas for other phases,they demonstrate similar behaviors as other additive alloying elements such as Ag and Cu do.
基金financially supported by the National Natural Science Foundation of China(NSFC)(21802003,51672007,11974023)the China Postdoctoral Science Foundation(No.2019M650337)the Science Foundation for High-Level Talents of Wuyi University,China(2018RC50)。
文摘Developing high-efficiency,stable and non-precious electrocatalysts for oxygen reduction reaction(ORR)is highly important for energy conversion and storage.Single atom catalysts(SACs)show good potential in enhancing ORR,however,the specifical control over the coordination surroundings around single metal center to intrinsically modify the electron structure is still a great challenge.Herein,we demonstrate that a 3 D hybrid MOF composed of cobalt doped ZIF-L and ZIF-8,featuring star morphology with six equal branches,can be used as an advanced precursor for making the Co SACs for greatly boosted ORR.The as-synthesized Co_(SA)-N-C exhibits excellent ORR activity with E_(1/2) of 0.891 V in alkaline medium,outperforming the commercial Pt/C by 39 m V.Moreover,the E_(1/2) of Co_(SA)-N-C(0.790 V)is merely 15 m V,less than that of Pt/C(0.805 V)in acid medium,which is among the best in the reported state-of-the-art SACs.DFT calculations demonstrate that the enhanced ORR performance is assigned to the formation of atomically isolated cobalt atom coordinated three N atoms and one C atom,which is easier to decrease the free energy of rate determining step and accelerate the ORR process than that of traditional cobalt atom coordinated four N atoms.In addition,a primary Zn-air battery with Co_(SA)-N-C cathode reveals a maximum power density of 92.2 m W cm^(-2) at 120.0 m A cm^(-2),far higher than that of commercial catalysts(74.2 m W cm^(-2) at 110.0 m A cm^(-2)).
基金the Natural Science Foundation of Sichuan Educational Bureau,No.(2001)149-01LA40the Natural Science Foundation of Sichuan Bureau of Science and Technology,No.(2003) 14-05JY029-103
文摘BACKGROUND： Structural and functional synaptic changes, as well as blood-brain barrier （BBB） changes, affect the micro-environment of nervous tissue and excitation, both of which play an important role in epilepsy. OBJECTIVE： To observe synaptic and BBB ultrastructural changes in the motor cortex of a rat epilepsy model induced by coriaria lacton, and to investigate the synaptic and BBB effects on the mechanism of epilepsy. DESIGN： A randomized controlled animal experiment. SETTING： Department of Histology and Embryology, Luzhou Medical College; and Electron Microscopy Laboratory, Luzhou Medical College. MATERIALS： Twenty healthy male Sprague Dawley rats, aged 8 weeks, were chosen for this study. The rats weighed （280 ± 50） g and were supplied by the Experimental Animal Center of Luzhou Medical College. Experimentation was performed in accordance with the ethical guidelines for the use and care of animals. The animals were randomly divided into a control group and an epilepsy group, with 10 rats in each group. METHODS： This study was performed at the Department of Histology and Embryology, and Electron Microscopy Laboratory, Luzhou Medical College between February and December 2006. According to the protocol, the epilepsy group was injected with 10 μ L/100 g coriaria lacton into the lateral ventricles to establish an epileptic model. The control group rats were not administered anything. Eight days after the model was established, all rats were anesthetized with ether. The motor cortex was removed and sectioned into ultrathin sections. Synaptic and BBB ultrastructural changes were observed by electron microscopy. MAIN OUTCOME MEASURES： （1）Structural changes of three different parts of the synapses, synaptic cleft width, postsynaptic density thickness, proportion of perforation synapses, curvature of synaptic interface, and length of active zones. （2）Capillary and BBB changes （endothelium, basement membrane, pericyte, and the astrocyte endfeet）. RESULTS： （1）Curvature of synaptic interface, length of active zones, thickness of postsynaptic density, and percentage of perforation synapses increased significantly. （2）There was significant edema in the endothelium, basement membrane, and the pericyte of the epilepsy group; the electron density of the basement membrane was reduced. CONCLUSION： （1） The coriaria lacton treatment altered synaptic ultrastructure, as well as BBB characteristics, in the epileptic rat model, and also improved synaptic transmission efficiency, as well as BBB permeability; （2）Synaptic and BBB ultrastructural changes might play an important role in the mechanism of epilepsy.
文摘AIM：To examine the expression of intercellular adhesion molecule-1 （ICAM-1） and lymphocyte function-associated antigen-1（LFA-1）expression on canals of Hering （COH）and bile ductules associated with the autoimmune process of bile duct destruction in primary biliary cirrhosis（PBC）．METHODS：Ten wedged liver biopsies of PBC（five cases each of stages 2 and 3）were studied. The liver specimens were processed for transmission electron microscopy. Immunohistochemistry was performed using anti-ICAM-1 and anti-LFA-1 mouse mAbs.In situ hybridization was done to examine the messenger RNA expression of ICAM-1 in formalin-fixed．paraffin-embedded sections using peptide nucleic acid probes and the catalyzed signal amplification （CSA）technique．Immunogold-silver staining for electron microscopy was Derrormed using anti-ICAM and anti-LFA-1 mouse mAbs．The immunogold particles on epithelial cells of bileductules and cholangiocytes of CoH cells were counted and analyzed semi-quantitatively．Western blotting was performed to confirm ICAM-1 protein expression．RESULTS：In liver tissues of PBC patients．immunohi-stochemistry showed aberrant ICAM-1 expression on the plasma membrane of epithelial cells lining bile ductules，and also on mature cholangiocytes but not on hepatocytes in CoH．LFA-1-positive lymphocytes were closely associated with epithelial cells in bile ductules．ICAM-1 expression at protein level was confirmed by Western blot．In situ hybridization demonstrated ICAM-1 mRNA expression in bile ductules and LFA-1 mRNA in lymphocytes infiltrating the bileductules．By immunoelectron microscopy，ICAM-1 was demonstrated on the basal suface of epithelial cells in bile ductules and on the luminal surfaces of cholangiocytes in damaged COH．Cells with intermediate morphology resembling progenitor cells in Coil were not labeled with ICAM-1 and LFA-1．CONCLUSION：De novo expression of ICAM-1 both on mature cholangiocytes in COH and epithelial cells in bile ductules in PBC implies that lymphocyte-induced destruction through adhesion by ICAM-1 and binding of LFA-1-expressing activated lymphocytes takes place not only in bile ductules but also in the COH．
基金financially supported by the Brazilian and Cearáresearch agencies CAPESFUNCAP
文摘Objective:To evaluate the antibacterial activity and neuroprotective capacity of the ethanolic and aqueous extracts of Tarenaya spinosa(T.spinosa)as well as to determine and quantify some of its polyphenols by high performance liquid chromatography with diode-array detection(HPLC-DAD).Methods:The bacterial Escherichia coli,Staphylococcus aureus and Pseudomonas aeruginosa strains,grown in Heart Agar Infusion,were tested.The drugs gentamicin,norfloxacin and imipenem were used to evaluate the modulating or antagonistic capacity of the T.spinosa extracts.The extract was analysed by HPLC-DAD to determine the main phenolic compounds.For the cell viability tests,individual heads of the Nauphoeta cinerea arthropod model were removed,homogenized in Trifluoromethyl ketone and centrifuged afterwards.Subsequently,20μL of NaN O_(2) were added to the biological material,except in the control group,to evaluate the protection capacity of the extracts.The homogenate of the insect heads was incubated for 2 h in tubes containing tetrazolium bromide.Results:HPLC-DAD demonstrated that the ethanolic extract of T.spinosa presented caffeic acid as the major compound.The ethanolic extract also showed neuroprotective effects at concentrations≥10μg/mL,while aqueous extract was shown to have a protective effect only at the concentration of 100μg/mL.The aqueous extract demonstrated a clinically relevant antibacterial activity against the Staphylococcus aureus multidrug resistant strain-MDR,with MIC 512μg/m L.However,when the extracts were associated with gentamicin and imipenem,a synergism was detected against Staphylococcus aureus and Escherichia coli MDR strains.Conclusions:Although it does not present an antibacterial action,the extracts of T.spinosa can be used in the pharmaceutical industries since its extracts show modulating action of drugs.Besides,these natural products have neuroprotective capacity.
基金supported by the National Key Research and Development Program of China(Grant No.2017YFC0601901)the National Natural Science Foundation of China(Grant No.61571019)。
文摘As a newly developed method for fabricating Josephson junctions,a focused helium ion beam has the advantage of producing reliable and reproducible junctions.We fabricated Josephson junctions with a focused helium ion beam on our 50 nm YBa_(2)Cu_(3)O_(7-δ)(YBCO)thin films.We focused on the junction with irradiation doses ranging from 100 to 300 ions/nm and demonstrated that the junction barrier can be modulated by the ion dose and that within this dose range,the junctions behave like superconductor–normal conductor–superconductor junctions.The measurements of the I–V characteristics,Fraunhofer diffraction pattern,and Shapiro steps of the junctions clearly show AC and DC Josephson effects.Our findings demonstrate high reproducibility of junction fabrication using a focused helium ion beam and suggest that commercial devices based on this nanotechnology could operate at liquid nitrogen temperatures.
基金supported in part by the Pennsylvania Infrastructure Technology Alliance,a partnership of Carnegie Mellon,Lehigh University,and the Commonwealth of Pennsylvania’s Department of Community and Economic Development(DCED)The authors recognize Reading Alloys(formerly affiliated with AMETEK Inc.,now a part of Kymera International),especially Muktesh Paliwal and Mike Marucci,for providing the Ti-6Al-4V powder used in this work and for assistance with the study+1 种基金This work was performed under the auspices of the U.S.Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344 and IM release number#LLNL-JRNL-838778The authors acknowledge partial support from the National Science Foundation under grant number DMR-2050916.IG appreciates the financial support from the Gallogly College of Engineering at the University of Oklahoma.
文摘The presence ofα/αon priorβ/βgrain boundaries directly impacts the final mechanical properties of the titanium alloys.Theβ/βgrain boundary variant selection of titanium alloys has been assumed to be unlikely owing to the high cooling rates in laser powder bed fusion(L-PBF).However,we hypothesize that powder characteristics such as morphology(non-spherical)and particle size(50–120μm)could affect the initial variant selection in L-PBF processed Ti-6Al-4V alloy by locally altering the cooling rates.Despite the high cooling rate found in L-PBF,results showed the presence ofβ/βgrain boundaryαlath growth inside two adjacent priorβgrains.Electron backscatter diffraction micrographs confirmed the presence ofβ/βgrain boundary variant selection,and synchrotron X-ray high-speed imaging observation revealed the role of the“shadowing effect”on the locally decreased cooling rate because of keyhole depth reduction and the consequentβ/βgrain boundaryαlath growth.The self-accommodation mechanism was the main variant selection driving force,and the most abundantα/αboundary variant was type 4(63.26°//[10553¯]).The dominance of Category IIαlath clusters associated with the type 4α/αboundary variant was validated using the phenomenological theory of martensite transformations and analytical calculations,from which the stress needed for theβ→αtransformation was calculated.
文摘A number of studies have focused on the beneficial properties of Curcumin (diferuloyl methane, used in South Asian cuisine and traditional medicine) such as the chemoprevention of cancer. Recent studies have also indicated that this material has significant benefits for the treatment of cancer and is currently undergoing several clinical trials. We have been interested in the application of this compound as a therapeutic agent for advanced prostate cancer, particularly the skeletal complications in this malignancy. Our earlier work indicated that this compound could inhibit the osteomimetic properties which occur in castration resistant prostate cancer cells, by interfering with the common denominators between these cancer cells and the bone cells in the metastatic tumor microenvironment, namely the osteoblasts and the osteoclast. We predicted that curcumin could break the vicious cycle of reciprocal stimulation that results in uncontrolled osteolysis in the bony matrix. In this work, we have evaluated the potential of this compound in inhibiting the bone metastasis of hormone refractory prostate cancer cells in an established animal model. Our results strongly suggest that curcumin modulates the TGF-βsignaling that occurs due to bone matrix degradation by up-regulating the metastasis inhibitory bone morphogenic protein-7 (BMP-7). This enhancement of BMP-7 in the context of TGF-β in the tumor microenvironment is shown to enhance the mesenchymal-to-epithelial transition. Most importantly, we show that as a result of BMP-7 up-regulation, a novel brown/beige adipogenic differentiation program is also up-regulated which plays a role in the inhibition of bone metastasis. Our results suggest that curcumin may subvert the TGF-β signaling to an alternative adipogenic differentiation program in addition to the previously established interference with the osteomimetic properties, thus inhibiting the bone metastatic processes in a chemopreventive as well as therapeutic setting.
文摘The genetic bases and molecular mechanisms involved in the assembly and function of the flagellum components as well as in the regulation of the flagellar movement are not fully understood, especially in humans. There are several causes for sperm immotility, of which some can be avoided and corrected, whereas other are related to genetic defects and deserve full investigation to give a diagnosis to patients. This review was performed after an extensive literature search on the online databases PubMed, ScienceDirect, and Web of Science. Here, we review the involvement of regulatory pathways responsible for sperm motility, indicating possible causes for sperm immotility. These included the calcium pathway, the cAMP-dependent protein kinase pathway, the importance of kinases and phosphatases, the function of reactive oxygen species, and how the regulation of cell volume and osmolarity are also fundamental components. We then discuss main gene defects associated with specific morphological abnormalities. Finally, we slightly discuss some preventive and treatments approaches to avoid development of conditions that are associated with unspecified sperm immotility. We believe that in the near future, with the development of more powerful techniques, the genetic causes of sperm immotility and the regulatory mechanisms of sperm motility will be better understand, thus enabling to perform a full diagnosis and uncover new therapies.
基金Supported by NOVO Nordisk Foundation(grant number 1013267)Savværksejer Jeppe Juhl og Hustru Ovita Juhls Mindelegat to Gr?nb?k HVillum Fonden to Nyengaard JR
文摘AIM To evaluate the liver regeneration capacity(LRC) after partial hepatectomy(PH) in experimental non-alcoholic steatohepatitis(NASH).METHODS Fifty-four female rats were fed a high-fat, high-cholesterol diet(HFCD, 65% fat, 1% cholesterol) or standard diet(STD) for 16 wk. A 70% PH was performed and the animals were euthanised before PH or 2 or 5 d postPH. LRC was evaluated using: The total number of Ki-67 positive hepatocytes in the caudate lobe, N(Ki-67, lobe) evaluated in a stereology-based design, the regenerated protein ratio(RPR), prothrombin-proconvertin ratio(PP), and m RNA expression of genes related to regeneration.RESULTS The HFCD NASH model showed significant steatosis with ballooning and inflammation, while no fibrosis was present. Mortality was similar in HFCD and STD animals following PH. HFCD groups were compared to respective STD groups and HFCD animals had a significantly elevated alanine transaminase at baseline(P < 0.001), as well as a significantly elevated bilirubin at day 2 after PH(P < 0.05). HFCD animals had a higher N(Ki-67, lobe) at baseline,(P < 0.0001), day 2 after PH(P = 0.06) and day 5 after PH(P < 0.025). We found no significant difference in RPR or PP neither 2 or 5 d post-PH. Expression of liver regeneration genes(e.g., hepatic growth factor) was higher at both day 2 and 5 post-PH in HFCD groups(P < 0.05).CONCLUSION NASH rats had a preserved LRC after hepatectomy when compared to STD rats. The methods and models of NASH are essential in understanding and evaluating LRC.
文摘The aim of the present work was to present the outcomes of the patients with Y-chromosome microdeletions treated by intracytoplasmic sperm injection （ICSI）, either using fresh （TESE） or frozen-thawed （TESE-C） testicular sperm and ejaculated sperm （EJAC）. The originality of this work resides in the comparisons between the different types of Y-microdeletions （AZFa, AZFb, and AZFc） and treatments, with detailed demographic, stimulation, embryological, clinical, and newborn （NB） outcomes. Of 125 patients with Y-microdeletions, 33 patients presented severe oligozoospermia （18 performed ICSI with ejaculated sperm） and 92 secretory azoospermia （65 went for TESE with 40 having successful sperm retrieval and performed ICSI）. There were 51 TESE treatment cycles and 43 TESE-C treatment cycles, with a birth of 19 NB （2 in AZFa/TESE-C, 12 in AZFc/TESE, and 5 in AZFc/TESE-C）. Of the 29 EJAC cycles, there was a birth of 8 NB （in AZFc）. In TESE and EJAC cycles, there were no significant differences in embryological and clinical parameters. In TESE-C cycles, there was a significant lower oocyte maturity rate, embryo cleavage rate and mean number of embryos transferred in AZFb, and a higher mean number of oocytes and lower fertilization rate in AZFc. In conclusion, although patients with AZFc microdeletions presented a high testicular sperm recovery rate and acceptable clinical outcomes, cases with AZFa and AZFb microdeletions presented a poor prognosis. Due to the reported heredity of microdeletions, patients should be informed about the infertile consequences on NB and the possibility of using preimplantation genetic diagnosis for female sex selection.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10374004, 90201037, and 50172001, the State Key Lab on Integrated 0ptoelectronics, and the National Center for Nanoscience and Technology, China.
文摘Single crystalline ZnSe nanowires with both zincblende and wurtzite structures have been synthesized via a chemical vapour deposition method under different growth conditions. The nanowires are usually 50-80nm in diameter, and several tens of microns in length. Room-temperature photoluminescence spectra from zincblende and wurtzite ZnSe nanowires show a broad luminescence band peaked at around 2. 71 e V and a deep level emission band peaked at around 2.00 eV, respectively. Effects of post-growth annealing on the photoluminescence of these nanowires have been investigated. Strong room-temperature band-edge emission could be obtained from the annealed zincblende ZnSe nanowires.
