Achieving High Dispersion of Pd in Small-Pore Zeolite SSZ-13: A High-Efficiency Low-Temperature NOx Adsorber.

Passive NO x adsorber (PNA) materials are primarily considered for reducing nitrogen oxide emissions during the low-temperature cold start of a motor vehicle. Pd/SSZ-13 has attracted considerable attention because of its outstanding hydrothermal stability and sulfur resistance. Optimizing the dispersion of precious metal Pd in Pd/SSZ-13 is crucial for enhancing PNA performance and nitrogen oxide adsorption capability. In this study, we prepared Pd/SSZ-13 using different methods and evaluated their influence on the NO x adsorption capability. The characterization results show that the dispersion of precious metal Pd in the Pd/SSZ-13 catalyst prepared by the quantitative ion-exchange method is as high as 92.13%, and the loading amount is as high as 98.93%. Pd predominantly exists as Pd2+, achieving near-total loading and further improving the catalyst's NO x adsorption capacity. This study offers innovative approaches and methods for applying Pd/SSZ-13 as a PNA material, serving as a reference for its further optimization and performance enhancement. Continued research into the preparation and adsorption performance of Pd/SSZ-13 materials could offer solutions to reduce motor vehicle nitrogen oxide emissions.

Therapeutic plasma exchange combined with ribavirin to rescue critical SFTS patients.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is a zoonotic infectious disease caused by the severe fever with thrombocytopenia syndrome virus (SFTSV). Endemic in East Asia, SFTS is characterized by an exceptionally high mortality rate. Presently, there is no established treatment for SFTS, particularly for patients in critical condition. In this study, we collected and analyzed laboratory and clinical data from 92 critically ill patients with SFTS treated at Weihai Municipal Hospital between 2019 and 2022. We hope that our study will provide some hints for the treatment of critically ill patients with SFTS. METHODS: A total of 92 critically ill patients with SFTS were included in this study. Of these patients, 45 received treatment with therapeutic plasma exchange (TPE) and ribavirin (referred to as the TPE group), while the remaining patients received only ribavirin (referred to as the non-TPE group). Clinical and laboratory parameters were analyzed retrospectively. RESULTS: The results showed significant improvements in multiple laboratory parameters following treatment with TPE and ribavirin, including white blood cell and neutrophil count, lactate dehydrogenase, creatine kinase isoenzyme-MB, prothrombin time, activated partial thromboplastin time, D-Dimer, serum sodium and copies of virus genomes. The combination of TPE with ribavirin demonstrated a significant reduction in mortality rates, with a mortality rate of 20.0% in the TPE group compared to 40.4% in the non-TPE group (P = 0.033). CONCLUSIONS: Our findings suggest that critically ill patients with SFTS who received TPE and ribavirin experienced improvements in both clinical and laboratory parameters. These results indicate that TPE combined with ribavirin may represent a promising novel therapeutic approach for managing critically ill patients with SFTS. However, comparative studies of large sample size or randomized clinical trials are warranted to confirm the effectiveness of this combination therapy in the treatment of severe SFTS cases.

Application of RNA sequencing to understand the response of rice seedlings to salt-alkali stress.

BACKGROUND: Salt-alkali stress represents one of the most stressful events with deleterious consequences for plant growth and crop productivity. Despite studies focusing on the effects of salt-alkali stress on morphology and physiology, its molecular mechanisms remain unclear. Here, we employed RNA-sequencing (RNA-seq) to understand how Na2CO3 stress inhibits rice seedling growth. RESULTS: Na2CO3 stress significantly inhibited the growth of rice seedlings. Through RNA-seq, many differentially expressed genes (DEGs) were shown to be potentially involved in the rice seedling response to salt-alkali stress. After 1-day and 5-day treatments, RNA-seq identified 1780 and 2315 DEGs in the Na2CO3-treated versus -untreated rice seedling shoots, respectively. According to the gene ontology enrichment and the Kyoto Encylopedia of Genes and Genomes annotation of DEGs, the growth-inhibition processes associated with salt-alkali stress involve a myriad of molecular events, including biosynthesis and metabolism, enzyme activity, and binding, etc. CONCLUSION: Collectively, the transcriptome analyses in the present work revealed several potential key regulators of plant response to salt-alkali stress, and might pave a way to improve salt-alkali stress tolerance in rice.

Template-free, controllable and scalable synthesis of poly(5-aminoindole) nanoparticles for printable electrochemical immunosensor with ultra-high sensitivity.

Conductive polymer polyindole derivatives have good conductivities and abundant functional groups, which would offer great potential for versatile applications including biosensors, bioelectronics and energy devices. However, the polyindole derivatives are mainly synthesized by the electropolymerization method on conductive electrode surfaces, which limits large-scale synthesis and practical applications. Herein, we explore a strategy of template-free, controllable and scalable synthesis of poly-5-aminoindole (PIn-5-NH2) nanoparticles (NPs) and demonstrate the application of PIn-5-NH2 NPs in printable multiplexed electrochemical biosensors with ultra-high sensitivity. The synthesis of PIn-5-NH2 NPs is based on a self-templated method since the In-5-NH2 monomer with amphiphilic structures can form micelles by self-assembly in an aqueous solution. The diameter of PIn-5-NH2 NPs could be controlled by adjusting the synthesis conditions, such as monomer concentration, oxidant/monomer ratio and reaction time. The PIn-5-NH2 NPs possess distinct features, including good conductivity, large surface area, and abundant -NH2 functional groups for covalent binding of the antibody, and therefore offer substantial possibilities for developing an all-printable process to fabricate multiplexed electrochemical immunosensors. The printed multiplexed electrochemical immunosensors on the basis of the aqueous suspension of PIn-5-NH2 NPs linked with antibodies can simultaneously detect multiple cancer markers, and exhibit high sensitivity and good selectivity. Our facile and scalable synthesis strategy would offer great opportunities for versatile applications of PIn-5-NH2 NPs.

Highly Conductive PPy-PEDOT:PSS Hybrid Hydrogel with Superior Biocompatibility for Bioelectronics Application.

Conductive polymer hydrogels (CPHs) hold significant promise in broad applications, such as bioelectronics and energy devices. Hitherto, the development of a facile and scalable synthesis method for CPHs with high electrical conductivity and biocompatibility has still been a challenge. Herein, we demonstrate highly conductive PPy-PEDOT:PSS hybrid hydrogels which are prepared by a simple solution-mixing method. This fabrication method involves the mixing of a pyrrole monomer with a PEDOT:PSS dispersion, followed by in situ chemical oxidative polymerization to form polypyrrole (PPy). The electrostatic interaction between negatively charged PSS and positively charged conjugated PPy facilitates the formation of PPy-PEDOT:PSS hybrid hydrogels. The conductivity of the PPy-PEDOT:PSS hybrid hydrogels is 867 S m-1. The PPy-PEDOT:PSS hybrid hydrogels show excellent biocompatibility. Moreover, the PPy-PEDOT:PSS hybrid hydrogels have a hierarchical porous structure which facilitates the 3D cell culture within the hydrogels. The PPy-PEDOT:PSS hybrid hydrogels exhibit excellent in situ biomolecular detection and real-time cell proliferation monitoring performance, indicating their potential as highly sensitive electrochemical biosensors for bioelectronics applications. Our strategy for the fabrication of CPHs with the electrostatic interaction between the negatively charged conductive polymer and positively charged conductive polymer would provide new opportunities for the design of highly conductive conjugated hydrogels for bioelectronics applications and energy devices.

LncRNA ANCR Suppresses the Progression of Hepatocellular Carcinoma Through the Inhibition of Wnt/ß-Catenin Signaling Pathway.

OBJECTIVE: Our study aimed to investigate the effect of anti-differentiation noncoding RNA (ANCR) on hepatocellular carcinoma (HCC) and its potential molecular mechanisms. METHODS: The expression of ANCR was detected by qRT-RCR in both HCC tissues and HCC cells. Moreover, the relationship between ANCR expression and clinical parameters in HCC patients was investigated. The proliferation, cell clones, migration, invasion and apoptosis of MHCC97H and HCCLM3 cells were measured by MTT assay, colony formation assay, transwell assay and flow cytometry, respectively. The expressions of N-cadherin, vimentin, E-cadherin, cleaved caspase-3, Bax, Bcl-2, Wnt1, ß-catenin and GSK-3ß in MHCC97H and HCCLM3 cells were measured by Western blot. RESULTS: Our results showed that ANCR was lowly expressed in both HCC tissues and HCC cells. ANCR expression was closely associated with tumor size, tumor-node-metastasis (TNM) stages and vascular invasion in HCC. ANCR could dramatically inhibit cell proliferation, migration and invasion, as well as promote apoptosis in MHCC97H and HCCLM3 cells. ANCR could significantly increase the expression of cleaved caspase-3, Bax, E-cadherin and GSK-3ß but reduce the expression of Bcl-2, N-cadherin, vimentin, Wnt1 and ß-catenin in MHCC97H and HCCLM3 cells. In addition, Wnt/ß-catenin pathway inhibitor (IWP-2) partially reversed the effects of silencing ANCR on the proliferation, migration, invasion and apoptosis of HCCLM3 cells. CONCLUSION: Our study demonstrated that ANCR can suppress cell proliferation, migration and invasion, as well as promote apoptosis of HCC cells via modulation of the Wnt/ß-catenin signaling pathway.

LncRNA RHPN1-AS1 Promotes Cell Proliferation, Migration and Invasion Through Targeting miR-7-5p and Activating PI3K/AKT/mTOR Pathway in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is a severe disease with high mortality in the world. Emerging evidence has suggested that lncRNAs play an important role in cancer progression, including HCC. This study aimed to comprehensively investigate the effect of lncRNA RHPN1 antisense RNA 1 (RHPN1-AS1) on HCC and its underlying molecular mechanism. In this study, we evaluated the expressions of lncRNA RHPN1-AS1 and miR-7-5p by qRT-RCR in both HCC tissue and HCC cells. Our findings showed that lncRNA RHPN1-AS1 was upregulated in HCC tissue and HCC cells, while miR-7-5p was downregulated. LncRNA RHPN1-AS1 expression in HCC patients was closely related to vascular invasion, tumor-node-metastasis (TNM) stage and barcelona clinic liver cancer (BCLC) stage. Furthermore, we quantified cell clone-formation ability, proliferation, migration and invasion of HCCLM3 and MHCC97 H cells using several assays (colony formation assay, 5-Ethynyl-2'-deoxyuridine (EdU) assay and transwell assay, respectively). Functional experiments confirmed that silencing lncRNA RHPN1-AS1 inhibited cell proliferation, migration and invasion in HCCLM3 and MHCC97 H cells. After that, bioinformatics analysis, dual luciferase reporter gene assay, qRT-PCR and western blot were used to investigate the molecular mechanism of lncRNA RHPN1-AS1 on HCC. Mechanistically, the rescue experiments demonstrated that miR-7-5p inhibitor reversed the inhibition effect of silencing lncRNA RHPN1-AS1 on HCCLM3 cells proliferation, migration and invasion. Moreover, silencing lncRNA RHPN1-AS1 also inhibited the activation of PI3K/AKT/mTOR pathway. Taken together our findings demonstrated that lncRNA RHPN1-AS1 could facilitate cell proliferation, migration and invasion via targeting miR-7-5p and activating PI3K/AKT/mTOR pathway in HCC.

Multifunctional hierarchical mesoporous silica and black phosphorus nanohybrids as chemo-photothermal synergistic agents for enhanced cancer therapy.

Synergistic therapy with high efficacy and low side effects is of great significance in cancer treatment, and therefore the elaborate design of advanced nanocarriers to benefit diverse loading requirements of size-varied therapy agents is of critical importance. Herein, we demonstrate a multifunctional drug carrier platform based on a hierarchical porous and -NH2-modified silica nanocarrier (FMSN) with a super high specific surface area and a large pore volume, which not only improves the loading capacity of both doxorubicin, a chemotherapeutic drug, and black phosphorus quantum dots (BPQDs), a kind of biocompatible photothermal agent, but also enhances the photothermal stability and biostability of the degradable BPQDs. The unique structure and surface design enable our multimodal platform with heat-stimulative, pH-responsive and sustained-release properties for chemo-photothermal synergistic cancer therapy. Both cytotoxicity experiments and in vivo study reveal that the combined therapy based on our multifunctional nanohybrids mediates the highest death rate of cancer cells compared to that of single chemotherapy or photothermal therapy. Our hierarchical mesoporous strategy provides an excellent drug delivery model for advanced chemo-photothermal synergistic targeted cancer therapy.

A highly sensitive label-free electrochemical immunosensor based on poly(indole-5-carboxylicacid) with ultra-high redox stability.

The high stability of redox signal is one of the most crucial factors in construction of electrochemical immunosensors. However, the redox-active species usually show low stability and poor conductivity, which inhibits their application in electrochemical immunosensors. In this work, we report that the conductive polymer poly(indole-5-carboxylic acid) (PIn-5-COOH) possesses ultra-high redox stability. The redox signal of PIn-5-COOH could remain 96.03% after 500 cyclic voltammery (CV) cycles in buffer solution with pH of 6.2, while the redox signals in most of the previous reports only remained less than 90% after 50 CV cycles. Our mechanism investigation indicated that the ultra-high redox stability of PIn-5-COOH should be attributed to its stable structure. The electrochemical immunosensors fabricated with PIn-5-COOH/MWCNTs-COOH nanocomposite showed a wide linear range from 0.001 ng mL-1 to 100 ng mL-1 and a low detection limit of 0.33 pg mL-1 for the detection of alpha fetoprotein. This study opens up a new avenue for the construction of electrochemical immunosensors with ultra-stable redox signal.

Rapid of cultivation dissimilatory perchlorate reducing granular sludge and characterization of the granulation process.

To remove high-strength perchlorate, dissimilatory perchlorate reducing granular sludge (DPR-GS) was first cultivated. Three identical UASB reactors were set up under different seed sludge and up-flow velocities (RAS: active sludge (AS) and constant up-flow velocities; RDGS: denitrifying granular sludge (DGS) and constant up-flow velocities; RDGS-f: DGS and fluctuating up-flow velocities). The AS in the RAS was completely granulated by day 117, while the DGS in the RDGS and RDGS-f were both shortened the granulation time to 99 days. In addition, the fluctuating up-flow velocity can better ensure rapid cultivation of DPR-GS. Removal of ClO4- loading rate with 7.20 kg/(m3·d) occurred in all three reactors. The results of extracellular polymeric substances (EPS) composition analysis indicated the polysaccharose (PS) promoted the formation of bio-aggregates, while the protein (PN) benefited the granulation of sludge. The analyses of the microbial communities indicated that Sulfurospirillum and Acinetobacter were the dominant dissimilatory perchlorate reducing bacteria.

A highly sensitive label-free electrochemical immunosensor based on an aligned GaN nanowires array/polydopamine heterointerface modified with Au nanoparticles.

Aligned GaN nanowire arrays show great potential not only in optoelectronic devices, but also in sensitive biosensor applications, owing to their excellent chemical stability and biocompatibility, as well as high electron mobility and surface-to-volume ratio. However, to construct electrochemical immunosensors, proper surface modification of GaN nanowires, which can enable efficient charge transfer and provide large densities of immobilization sites for antibodies to anchor, is still challenging. Herein we demonstrate a highly sensitive label-free electrochemical immunosensing platform based on the integration of polydopamine (PDA) on a GaN nanowire surface. The PDA polymer was self-assembled on GaN nanowire surfaces via organic polymerization. The interface dipole layer generated at the GaN nanowire array/PDA polymer heterointerface enabled efficient charge transfer. The aligned GaN nanowire array/PDA hybrids were further modified with gold nanoparticles for subsequent covalent binding of antibodies. The fabricated immunosensor yielded a wide linear range between 0.01 and 100 ng ml-1 and a detection limit as low as 0.003 ng ml-1 for the detection of alpha-fetoprotein (AFP). The immunosensor showed good selectivity, reproducibility, and stability and was utilized in human serum samples for AFP detection. This work demonstrates the superiority of taking advantage of a nanowire array configuration and a semiconductor/polymer heterointerface in an immunosensing platform for sensitivity enhancement.

Capping experiments reveal multiple surface active sites in CeO2 and their cooperative catalysis.

Understanding of surface active sites (SAS) of CeO2 is crucial to its catalytic applications. In the present study, we have employed capping experiments, DFT calculations, and spectroscopic characterization to study pristine CeO2 catalyst. We find that multiple SAS coexist on the CeO2 surface: oxygen vacancies as redox sites and the coordinately unsaturated Ce cations near the oxygen vacancies and the neighboring oxygen ions as Lewis acid-base sites. Dimethylsulfoxide (DMSO), pyridine, and benzoic acid are utilized to cap the redox sites, Lewis acid sites, and base sites, respectively. Selective capping on the redox site does not have much effect on the acid-base catalysis, and vice versa, indicating the distinct surface proximity and independent catalysis of these SAS. We draw attention to a relationship between the well-known redox sites and the surface Lewis acid and Lewis base pairs on CeO2 surface, which are responsible for driving various heterogeneous catalytic reactions.

Oxygen self-doped g-C3N4 with tunable electronic band structure for unprecedentedly enhanced photocatalytic performance.

As a fascinating conjugated polymer, graphitic carbon nitride (g-C3N4) has attracted much attention for solving the worldwide energy shortage and environmental pollution. In this work, for the first time we report oxygen self-doping of solvothermally synthesized g-C3N4 nanospheres with tunable electronic band structure via ambient air exposure for unprecedentedly enhanced photocatalytic performance. Various measurements, such as XPS, Mott-Schottky plots, and density functional theory (DFT) calculations reveal that such oxygen doping can tune the intrinsic electronic state and band structure of g-C3N4via the formation of C-O-C bond. Our results show that the oxygen doping content can be controlled by the copolymerization of the precursors. As a consequence, the oxygen doped g-C3N4 shows excellent photocatalytic performance, with an RhB photodegradation rate of 0.249 min-1 and a hydrogen evolution rate of 3174 µmol h-1 g-1, >35 times and ∼4 times higher than that of conventional thermally made pure g-C3N4 (0.007 min-1 and 846 µmol h-1 g-1, respectively) under visible light. Our work introduces a new route for the rational design and fabrication of doping modified g-C3N4 photocatalyst for efficient degradation of organic pollutants and H2 production.

Cocatalyzing Pt/PtO Phase-Junction Nanodots on Hierarchically Porous TiO2 for Highly Enhanced Photocatalytic Hydrogen Production.

Phase-junctions between a cocatalyst and its semiconductor host are quite effective to enhance the photocatalytic activity and are widely studied, while reports on the phase-juncted cocatalyst are still rare. In this work, we report the deposition of the Pt/PtO phase-juncted nanodots as cocatalyst via NaOH modification of an interconnected meso-macroporous TiO2 network with high surface area and inner-particle mesopores to enhance the performance of photocatalytic H2 production. Our results show that NaOH modification can largely influence Pt/PtO phase-juncted nanodot formation and dispersity. Compared to the TiO2 nanoparticles, the hierarchically meso-macroporous TiO2 network containing 0.18 wt % Pt/PtO phase-juncted cocatalyst demonstrates a highest photocatalytic H2 rate of 13 mmol g-1 h-1 under simulated solar light, and possesses a stable cycling activity without obvious decrease after five cycles. Such high H2 production performance can be attributed to both the phase-juncted Pt/PtO providing more active sites while PtO suppresses the undesirable hydrogen back reaction, and the special hierarchically porous TiO2 network with inner-particle mesopores presenting short diffusion path lengths for photogenerated electrons and enhanced light harvesting efficiency. This work suggests that Pt/PtO phase-juncted cocatalyst on hierarchically porous TiO2 nanostructures is a promising strategy for advanced photocatalytic H2 production.

Thermal behaviors, nonisothermal decomposition reaction kinetics, thermal safety and burning rates of BTATz-CMDB propellant.

The composite modified double base (CMDB) propellants (nos. RB0601 and RB0602) containing 3,6-bis (1H-1,2,3,4-tetrazol-5-yl-amino)-1,2,4,5-tetrazine (BTATz) without and with the ballistic modifier were prepared and their thermal behaviors, nonisothermal decomposition reaction kinetics, thermal safety and burning rates were investigated. The results show that there are three mass-loss stages in TG curve and two exothermic peaks in DSC curve for the BTATz-CMDB propellant. The first two mass-loss stages occur in succession and the temperature ranges are near apart, and the decomposition peaks of the two stages overlap each other, inducing only one visible exothermic peak appear in DSC curve during 350-550 K. The reaction mechanisms of the main exothermal decomposition processes of RB0601 and RB0602 are all classified as chemical reaction, the mechanism functions are f(alpha)=(1-alpha)(2), and the kinetic equations are dalpha/dt = 10(19.24)(1-alpha)(2)e(-2.32x10(4)/T) and dalpha/dt = 10(20.32)(1-alpha)(2)e(-2.32x10(4)/T). The thermal safety evaluation on the BTATz-CMDB propellants was obtained. With the substitution of 26% RDX by BTATz and with the help of the ballistic modifier in the CMDB propellant formulation, the burning rate can be improved by 89.0% at 8 MPa and 47.1% at 22 MPa, the pressure exponent can be reduced to 0.353 at 14-20 MPa.

Thermal decomposition of 3,4-bis(4'-aminofurazano-3') furoxan.

The thermal decomposition of 3,4-bis(4'-aminofurazano-3') furoxan (BAFF) was studied by DSC, TG, the combination technique of in situ thermolysis cell with rapid-scan Fourier transform infrared spectroscopy (thermolysis/RSFT-IR) and the fast thermolysis probe with rapid-scan Fourier transform infrared spectroscopy (fast thermolysis/RSFT-IR). The result shows that the melting point of BAFF is 168.4 degrees C, the peak temperatures of the two exothermic peaks are respectively 260.4 degrees C and 338.8 degrees C on DSC curve. The apparent activation energy E(a) and the pre-exponential factor A are respectively 122.21 kJ mol(-1) and 10(9.89)s(-1) for major exothermic decomposition process of BAFF. The kinetic equation of major exothermic decomposition for BAFF is dalpha/dt=10(10.07)exp(-1.46993 x 10(4)/T)(1-alpha) [-ln(1-alpha)](1/3). The thermal decomposition gaseous products of BAFF consist of CO(2), NO(2), N(2)O and NO. The BAFF is shown by IR spectroscopy to convert to ammonium dicyanamide (NH(4)[N(CN)(2)]), cyclic azine residues (melamine or melamine-like).

Johne's disease in cattle is associated with enhanced expression of genes encoding IL-5, GATA-3, tissue inhibitors of matrix metalloproteinases 1 and 2, and factors promoting apoptosis in peripheral blood mononuclear cells.

Infection of ruminants with Mycobacterium avium subspecies paratuberculosis (M. paratuberculosis) leads to a chronic and often fatal granulomatous enteritis known as Johne's disease. Most infections with M. paratuberculosis occur during the first 6 months of life, and there is some evidence for transmission in utero. Once established, infections typically exist in a subclinical state for several years. Recent gene-expression profiling studies suggested the hypothesis that inherent gene-expression profiles in peripheral blood mononuclear cells (PBMCs) from M. paratuberculosis-infected cattle may be different than expression profiles in PBMCs from uninfected controls. If true, this would suggest that it is possible to identify an M. paratuberculosis infection "signature" through transcriptional profiling of peripheral immune cells. In addition, identification of groups or classes of genes showing inherently different expression in PBMCs from M. paratuberculosis-infected cattle relative to PBMCs from uninfected controls might highlight important interactions between this pathogen and the host immune system. In this report, we describe studies aimed at testing this hypothesis. Our novel results indicate that, indeed expression profiles of at least 42 genes are inherently different in freshly isolated PBMCs from M. paratuberculosis-infected cattle when compared to similar cells from uninfected controls. Gene-expression differences observed following microarray analysis were verified and expanded upon by quantitative real-time PCR (Q-RT-PCR). Our results indicate that T cells within PBMCs from M. paratuberculosis-infected cows have adopted a predominant Th 2-like phenotype (enhanced expression of IL-5, GATA 3, and possibly IL-4 mRNA), that cells within infected cow PBMCs may exhibit tissue remodeling deficiencies through higher expression of tissue inhibitor of matrix metalloproteinase (TIMP) 1 and TIMP2 RNA and lower expression of matrix metalloproteinase (MMP) 14 RNA than similar cells from healthy controls, and that cells within the PBMC population of M. paratuberculosis-infected cows are likely poised for rapid apoptosis (upregulation of CIDE-A, Bad, TNFRI, and Fas).

Generation of a bovine oocyte cDNA library and microarray: resources for identification of genes important for follicular development and early embryogenesis.

The oocyte is a key regulator of ovarian folliculogenesis and early embryonic development. However, the composition of the oocyte transcriptome and identities and functions of key oocyte-specific genes involved in the above processes are relatively unknown. Using a PCR-based cDNA amplification method (SMART technology), we constructed a bovine oocyte cDNA library. Analysis of 230 expressed sequence tags (ESTs) from this library identified 102 unique sequences. Although some correspond to housekeeping genes (e.g., ribosomal protein L15) and some represent genes previously known to be expressed in oocytes and other tissues, most encode for genes whose expression in mammalian oocytes has not been reported previously (e.g., cocaine- and amphetamine-regulated transcript) or genes of unknown function. Sixteen did not show significant sequence similarity to any entries in the GenBank database and were classified as novel. Using over 2,000 unsequenced, randomly selected cDNA clones from the library, we constructed an oocyte microarray and performed experiments to identify genes preferentially expressed in fetal ovary (an enriched source of oocytes) relative to somatic tissues. Eleven clones were identified by microarray analysis with consistently higher expression in fetal ovaries (collected from animals at days 210-260 of gestation) compared with spleen and liver. DNA sequence analysis of these clones revealed that two correspond to JY-1, a novel bovine oocyte-specific gene. The remaining nine clones represent five identified genes and one additional completely novel gene. Increased abundance of mRNA in fetal ovary for five of the six genes identified was confirmed by real-time PCR. Results demonstrate the potential utility of these unique resources for identification of oocyte-expressed genes potentially important for reproductive function.