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With the scaling of lateral dimensions in advanced transistors, an increased gate capacitance is desirable both to retain the control of the gate electrode over the channel and to reduce the operating voltage1. This led to a fundamental change in the gate stack in 2008, the incorporation of high-dielectric-constant HfO2 (ref. 2), which remains the material of choice to date. Here we report HfO2-ZrO2 superlattice heterostructures as a gate stack, stabilized with mixed ferroelectric-antiferroelectric order, directly integrated onto Si transistors, and scaled down to approximately 20 ångströms, the same gate oxide thickness required for high-performance transistors. The overall equivalent oxide thickness in metal-oxide-semiconductor capacitors is equivalent to an effective SiO2 thickness of approximately 6.5 ångströms. Such a low effective oxide thickness and the resulting large capacitance cannot be achieved in conventional HfO2-based high-dielectric-constant gate stacks without scavenging the interfacial SiO2, which has adverse effects on the electron transport and gate leakage current3. Accordingly, our gate stacks, which do not require such scavenging, provide substantially lower leakage current and no mobility degradation. This work demonstrates that ultrathin ferroic HfO2-ZrO2 multilayers, stabilized with competing ferroelectric-antiferroelectric order in the two-nanometre-thickness regime, provide a path towards advanced gate oxide stacks in electronic devices beyond conventional HfO2-based high-dielectric-constant materials.
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Ultrathin ferroelectric materials could potentially enable low-power perovskite ferroelectric tetragonality logic and nonvolatile memories1,2. As ferroelectric materials are made thinner, however, the ferroelectricity is usually suppressed. Size effects in ferroelectrics have been thoroughly investigated in perovskite oxides-the archetypal ferroelectric system3. Perovskites, however, have so far proved unsuitable for thickness scaling and integration with modern semiconductor processes4. Here we report ferroelectricity in ultrathin doped hafnium oxide (HfO2), a fluorite-structure oxide grown by atomic layer deposition on silicon. We demonstrate the persistence of inversion symmetry breaking and spontaneous, switchable polarization down to a thickness of one nanometre. Our results indicate not only the absence of a ferroelectric critical thickness but also enhanced polar distortions as film thickness is reduced, unlike in perovskite ferroelectrics. This approach to enhancing ferroelectricity in ultrathin layers could provide a route towards polarization-driven memories and ferroelectric-based advanced transistors. This work shifts the search for the fundamental limits of ferroelectricity to simpler transition-metal oxide systems-that is, from perovskite-derived complex oxides to fluorite-structure binary oxides-in which 'reverse' size effects counterintuitively stabilize polar symmetry in the ultrathin regime.
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An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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In this Letter, the first name of author Bhagwati Prasad was misspelled Bhagawati. This error has been corrected online.
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Negative capacitance is a newly discovered state of ferroelectric materials that holds promise for electronics applications by exploiting a region of thermodynamic space that is normally not accessible1-14. Although existing reports of negative capacitance substantiate the importance of this phenomenon, they have focused on its macroscale manifestation. These manifestations demonstrate possible uses of steady-state negative capacitance-for example, enhancing the capacitance of a ferroelectric-dielectric heterostructure4,7,14 or improving the subthreshold swing of a transistor8-12. Yet they constitute only indirect measurements of the local state of negative capacitance in which the ferroelectric resides. Spatial mapping of this phenomenon would help its understanding at a microscopic scale and also help to achieve optimal design of devices with potential technological applications. Here we demonstrate a direct measurement of steady-state negative capacitance in a ferroelectric-dielectric heterostructure. We use electron microscopy complemented by phase-field and first-principles-based (second-principles) simulations in SrTiO3/PbTiO3 superlattices to directly determine, with atomic resolution, the local regions in the ferroelectric material where a state of negative capacitance is stabilized. Simultaneous vector mapping of atomic displacements (related to a complex pattern in the polarization field), in conjunction with reconstruction of the local electric field, identify the negative capacitance regions as those with higher energy density and larger polarizability: the domain walls where the polarization is suppressed.
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PURPOSE: This study aimed to assess the efficacy and safety outcome of covered stents (CSs), as compared with bare-metal stents (BMSs), for the treatment of patients with aortoiliac occlusive disease (AIOD). MATERIALS AND METHODS: A systematic literature search was conducted in PubMed, Embase, and Cochrane Library up to August 2023 to identify all studies comparing efficacy and safety outcomes of CSs versus BMSs for treating AIOD. Our outcome was primary patency, secondary patency, technical success, ankle-brachial index (ABI) variation, target lesion revascularization (TLR), limb salvage, complications, and long-term survival. Dichotomous outcomes were pooled as relative risks (RR) or hazard ratio with the 95% confidence interval (CI). Continuous outcomes were pooled as weighted mean differences and 95% CI. Model selection was based on the heterogeneity of the included studies. RESULTS: There were 10 studies (2 randomized controlled trials, 8 retrospective cohort studies), comprising 1676 sample size. Compared with BMSs, CSs use was associated with better primary patency of patients with a Trans-Atlantic Inter-Society Consensus II (TASC) D lesion (RR, 1.15, 95% CI, 1.04 to 1.27, p=0.007), TLR (RR, 0.39, 95% CI, 0.27 to 0.56, p<0.001), technical success (RR, 1.01, 95% CI, 1.00 to 1.02, p=0.010), and long-term survival (RR, 1.06, 95% CI, 1.01 to 1.11, p=0.020). There is no difference between CSs and BMSs regarding primary patency of all patients, secondary patency, variation in ABI, limb salvage, and complications. CONCLUSIONS: Compared with BMSs, CSs used in AIOD was associated with more favorable primary patency in patients with TASC D lesions, TLR, technical success rates, and patient long-term survival. These results provide evidence of the advantages of using CSs for AIOD treatment. Future studies focusing on long-term variations in ABI, primary patency of different degrees of calcification, vascular segments, and TASC classification are warranted. CLINICAL IMPACT: Although several studies evaluated the clinical efficacy of CS in the context of AIOD treatment, the significance and consistency of these findings were not determined to date. We found that CS was used in AIOD associated with better technical success rate, long-term patient survival, lower target lesion revascularization, and higher primary patency of patients with a Trans-Atlantic Inter-Society Consensus II D lesion when compared with BMSs. Our study provides evidence supporting the superiority of CSs over BMSs in the treatment of AIOD, and furnishing clinicians with guidance for treatment decisions.
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The feather growth rate in chickens included early and late feathering. We attempted to characterize the genes and pathways associated with the feather growth rate in chickens that are not in agreement with Mendelian inheritance. Gene expression profiles in the hair follicle tissues of late-feathering cocks (LC), early-feathering cocks (EC), late-feathering hens (LH), and early-feathering hens (EH) were acquired using RNA sequencing (RNA-seq), mass spectrometry (MS), and quantitative reverse transcription PCR (qRTPCR). A total of 188 differentially expressed genes (DEGs) were ascertained in EC vs. LC and 538 DEGs were identified in EH vs. LH. We observed that 14 up-regulated genes and 9 down-regulated genes were screened both in EC vs. LC and EH vs. LH. MS revealed that 41 and 138 differentially expressed proteins (DEPs) were screened out in EC vs. LC and EH vs. LH, respectively. Moreover, these DEGs and DEPs were enriched in multiple feather-related pathways, including JAK-STAT, MAPK, WNT, TGF-ß, and calcium signaling pathways. qRT-PCR assay showed that the expression of WNT8A was decreased in LC compared with EC, while ALK and GRM4 expression were significantly up-regulated in EH relative to LH. This study helps to elucidate the potential mechanism of the feather growth rate in chickens that do not conform to genetic law.
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Granulosa cell (GC) apoptosis is the main trigger of follicular atresia. MicroRNAs (miRNAs) are 18-22 nt RNAs whose function is primarily determined by their extended seed region and are considered to be involved in the biological functions of follicular development, including follicular atresia, folliculogenesis, and oogenesis. MiR-138-5p is known to act on chicken GCs. In this study, we found that miR-138-5p was enriched in reproductive organs, such as the uterus and ovaries. To examine whether miR-138-5p could regulate the biological process of GCs, miR-138-5p was examined by transfection of cells with a mimic or inhibitor of miR-138-5p. Expression levels of caspase-3 and caspase-9 mRNA and protein were markedly increased or decreased after transfection of the mimic or inhibitor, respectively. Furthermore, following miR-138-5p inhibition, SIRT1, one of the target genes of miR-138-5p, was found to increase the mRNA, which is correlated with the increased levels of BCL2 expression, an anti-apoptotic gene in the chicken GCs. These results suggest that miR-138-5p promotes apoptosis in chicken GCs by targeting SIRT1.
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Células da Granulosa , MicroRNAs , Feminino , Animais , Células da Granulosa/metabolismo , Galinhas/genética , Galinhas/metabolismo , Sirtuína 1/genética , Sirtuína 1/metabolismo , Atresia Folicular/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Apoptose/genética , RNA Mensageiro/metabolismo , Proliferação de Células/genéticaRESUMO
Broodiness, a maternal behavior, is accompanied by the atresia of follicles and the serious degradation of poultry reproductive performance. The comparison of follicles between brooding and laying hens is usually an ideal model for exploring the regulation mechanism of follicle atresia. In this study, we selected three brooding hens and three laying hens to collect their follicles for whole transcriptome sequencing. The results demonstrated different expression patterns between the follicles of brooding hens and laying hens. In the top 10 differentially expressed genes with the highest expression, MMP10 was relatively low expressed in the follicles of brooding hens, but other nine genes were relatively highly expressed, including LRR1, RACK1, SPECC1L, ABHD2, COL6A3, RPS17, ATRN, BIRC6, PGAM1 and SPECC1L. While miR-21-3p, miR-146a-5p, miR-142-5p and miR-1b-3p were highly expressed in the follicles of brooding hen, miR-106-5p, miR-451, miR-183, miR-7, miR-2188-5p and miR-182-5p were lowly expressed in brooding hen. In addition, we identified 124 lncRNAs specifically expressed in the follicles of brooding hens and 147 lncRNAs specifically expressed in the follicles of laying hens. Our results may provide a theoretical basis for further exploration of the molecular mechanism of broodiness in broilers.
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MicroRNAs , RNA Longo não Codificante , Feminino , Animais , Galinhas/genética , RNA Longo não Codificante/genética , Atresia Folicular , Perfilação da Expressão Gênica/veterinária , MicroRNAs/genética , Transcriptoma/genéticaRESUMO
Previous studies have shown that the feather growth rate of chicks is determined by two alleles located on the sex chromosome Z; however, in chicken production, feathering is usually not consistently controlled by the sex chromosome. To identify whether the feathering rate is related to autosomal inheritance, whole-genome resequencing was performed in eight chickens with slow- and fast-feathering rate. A total of 54,984 autosomal single nucleotide polymorphisms (SNPs) were identified, including 393 and 376 exonic SNPs in slow-feathering and fast-feathering chickens, respectively. Mutated genes were mainly involved in response to stimuli and growth and reproduction processes. Mutated genes related to slow-feathering rate were mainly involved in wingless-type MMTV integration site signaling pathway and mitogen-activated protein kinase signaling pathway, whereas mutated genes associated with fast-feathering rate were primarily enriched in autophagy, calcium signaling pathway, extracellular matrix-receptor interaction, and Focal adhesion processes. Importantly, two SNPs, involved in feather development, were found in the exonic regions of Wnt signaling genes. These results shed new light on the relationship between genetic mutation and feather growth rate from the perspective of autosomal inheritance and may have economic significance in chicken breeding.
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Galinhas , Polimorfismo de Nucleotídeo Único , Alelos , Animais , Galinhas/genética , Plumas , Proteínas Quinases Ativadas por Mitógeno/genética , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
Sichuan mountainous black-bone (SMB) chicken is a small-sized black-feathered chicken breed with low amount of meat, while Dahen (DH) chicken has a larger body size and a faster growth rate. MicroRNAs (miRNAs) are involved in various physiological processes, but their role in chicken muscle growth remains unclear. We aimed to investigate the miRNAs and pathways participating in the muscle growth of chicken. MiRNA profiles of four SMB chickens and four DH chickens were detected by small RNA sequencing. A total of 994 known miRNAs were identified, among which gga-miR-1a-3p, gga-miR-148-3p and gga-miR-133a-3p exhibited the highest enrichment in both breeds of chickens. Thirty-two miRNAs were differently expressed between SMB and DH chickens. The differently expressed miRNAs were mainly associated with fatty acid metabolism, immunity and MAPK activation-related processes. Kyoto encyclopaedia of genes and genomes (KEGG) analysis showed that miRNAs were involved in the immunity-related and MAPK signalling pathways. Moreover, miR-204 was downregulated in DH chicken compared with SMB chicken, and significantly inhibited the expression of MAP3K13, which is involved in the MAPK pathway. It was confirmed through luciferase reporter assays that miR-204 specifically inhibited the activity of MAP3K13. Our results helped demonstrate the potential molecular mechanisms of muscle growth in chickens and provide valuable information for chicken breeding.
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Galinhas/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , MicroRNAs/metabolismo , Músculo Esquelético/crescimento & desenvolvimento , Animais , Linhagem Celular , Galinhas/genética , Regulação para Baixo , Fibroblastos , Genoma , MAP Quinase Quinase Quinases/genética , MAP Quinase Quinase Quinases/metabolismo , MicroRNAs/genética , Reação em Cadeia da Polimerase em Tempo Real/veterináriaRESUMO
Objective: The goal of this study was to investigate the mechanisms of muscle growth and development of three chicken breeds. Participants: Eighteen chickens, including three different breeds with different growth speeds (White Broiler, Daheng, and Commercial Layers of Roman), were used. Methods: Total RNA from breast muscle of these chickens was subjected to a gene expression microarray. Differentially expressed genes (DEGs) were screened and functional enrichment analysis was performed using DAVID. Seven DEGs were confirmed by quantitative reverse transcription PCR. Results: Overall, 8,398 DEGs were found among the different lines. The DEGs between each two lines that were unique for a developmental stage were greater than those that were common during all stages. Functional analysis revealed that DEGs across the entire developmental process were primarily involved in positive cell proliferation, growth, cell differentiation, and developmental processes. Genes involved in muscle regulation, muscle construction, and muscle cell differentiation were upregulated in the faster-growing breed compared to the slower-growing breed. DEGs including myosin heavy chain 15 (MYH15), myozenin 2 (MYOZ2), myosin-binding protein C (MYBPC3), insulin-like growth factor 2 (IGF2), apoptosis regulator (BCL-2), AP-1 transcription factor subunit (JUN), and AP-1 transcription factor subunit (FOS) directly regulated muscle growth or were in the center of the protein-protein interaction network. Pathways, including the extracellular matrix (ECM)-receptor interaction, mitogen-activated protein kinase (MAPK) signaling pathway, and focal adhesion, were the most enriched DEGs between lines or within lines under different developmental stages. Conclusions: Genes involved in muscle construction and cell differentiation were differentially expressed among the three breeds.
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Galinhas/genética , Transcriptoma , Animais , Cruzamento , Galinhas/crescimento & desenvolvimento , Biologia Computacional , Feminino , Perfilação da Expressão Gênica/veterinária , Desenvolvimento Muscular/genética , Análise de Sequência com Séries de Oligonucleotídeos/veterinária , Músculos Peitorais/crescimento & desenvolvimentoRESUMO
Objective: Radical hysterectomy has long been considered as the standard surgical treatment for early-stage cervical cancer (IA2 to IB1 stages), according to the 2009 International Federation of Obstetrics and Gynecology. This study aims to conduct an in-depth evaluation of the effectiveness and safety of non-radical surgery as an alternative treatment for patients with early-stage cervical cancer. Methods: A systematic search of online databases including PubMed, Embase, and the Cochrane Library was conducted to identify relevant literature on surgical treatment options for early-stage cervical cancer. Keywords such as "cervical cancer," "conservative surgery," "early-stage," "less radical surgery," and "simple hysterectomy" were used. Meta-analysis was performed using Stata 15.0 software, which included randomized controlled trials (RCTs) and cohort studies. Results: This meta-analysis included 8 eligible articles covering 9 studies, with 3,950 patients in the simple hysterectomy (SH) surgery group and 6,271 patients in the radical hysterectomy (RH) surgery group. The results indicate that there was no significant difference between the two groups in terms of the Overall Survival (OS) (HR = 1.04, 95% CI: 0.86-1.27, p = 0.671; Heterogeneity: I2 = 33.8%, p = 0.170), Disease Free Survival (DFS) (HR = 1.39, 95% CI: 0.59-3.29, p = 0.456; Heterogeneity: I2 = 0.0%, p = 0.374), Cervical Cancer Specific Survival (CCSS) (HR = 1.11, 95% CI: 0.80-1.54, p = 0.519; Heterogeneity: I2 = 11.9%, p = 0.287) and recurrence rate (RR = 1.16, 95% CI: 0.69-1.97, p = 0.583; Heterogeneity: I = 0.0%, p = 0.488). However, the mortality rate (RR = 1.35, 95% CI: 1.10-1.67, p = 0.006; Heterogeneity: I2 = 35.4%, p = 0.158) and the rate of postoperative adjuvant therapy (RR = 1.59, 95% CI: 1.16-2.19, p = 0.004; Heterogeneity: I2 = 92.7%, p < 0.10) were higher in the SH group compared to those in the RH group. On the other hand, the incidence of surgical complications was lower in the SH group (RR = 0.36, 95% CI: 0.21-0.59, p = 0.004; Heterogeneity: I2 = 0.0%, p = 0.857) than that in the RH group. Subgroup analysis revealed that patients in the IB1 stage SH group had a significantly higher mortality rate compared to those in the RH group (RR = 1.59, 95% CI: 1.23-2.07, p < 0.001; Heterogeneity: I2 = 0.0%, p = 0.332). However, there was no significant difference in mortality rates between the two groups for patients at stage IA2 (RR = 0.84, 95% CI: 0.54-1.30, p = 0.428; Heterogeneity: I2 = 26.8%, p = 0.243). In the subgroups positive for Lymphovascular Space Invasion (LVSI), patients in the SH group had a significantly higher mortality rate than those in the RH group (RR = 1.34, 95% CI: 1.09-1.65, p = 0.005; Heterogeneity: I2 = 41.6%, p = 0.128). However, in the LVSI-negative subgroups, there was no significant difference in mortality rates between the two groups (RR = 0.33, 95% CI: 0.01-8.04, p = 0.499). Conclusion: For patients with early-stage cervical cancer patients at IA2 without LVSI involvement, comparisons between the two groups in terms of OS, DFS, CCSS, recurrence rate, and mortality rates revealed no statistically significant differences, indicating that the choice of surgical approach does not affect long-term survival outcomes for this specific patient group. For patients at IB1 and IA2 stages with LVSI involvement, while there were no significant differences between the two groups in OS, DFS, CSS, and recurrence rate, a significant increase in mortality rates was observed in the SH group. This indicates a potential elevated risk of mortality associated with SH in this subset of patients. Notably, the incidence of surgical complications was significantly lower in the SH group compared to the RH group, highlighting the safety profile of SH in this context. Significantly, among patients in the SH group, an increase in the rate of postoperative adjuvant treatment is associated with a higher occurrence of treatment-related complications. To facilitate more precise patient selection for conservative surgical management, future prospective studies of superior quality are imperative to gain deeper insights into this matter. Systematic review registration: PROSPERO (CRD42023451609: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023451609).
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BACKGROUND: Autologous arteriovenous fistulae (AVFs) are the best type of vascular access in patients with kidney failure. However, the conventional technique has a high failure rate. We performed a randomised controlled trial to investigate whether the no-touch technique has a higher maturation and patency rate than that of the conventional technique for creating AVFs. METHODS: This study was a single-centre randomised controlled trial involving patients with kidney failure requiring an AVF for haemodialysis access. A total of 179 patients undergoing their first radial artery-cephalic fistula were randomized 1:1 to the no-touch technique (n = 90) or conventional technique (n = 89). The maturation and patency rate of the two techniques were compared and analysed. RESULTS: The preoperative baseline data showed no differences between groups. When comparing the no-touch technique to the conventional technique, the maturation rate was 93% vs. 89% and the 1-year primary function patency was 72% vs. 62%, respectively. Factors associated with AVF failure included age > 55 years (OR = 2.417, 95% CI 1.242-4.703), female sex (OR = 2.149, 95% CI 1.099-4.202), and vein diameter ≤ 1.8 mm (OR = 3.664, 95% CI 1.714-7.832). For patients with small veins the maturation rate was 92.98% vs. 80% and the 1-year primary function patency was 68.42% vs. 40% for the no-touch technique and conventional technique, respectively. CONCLUSIONS: The no-touch technique has a higher maturation and patency rate than the conventional technique for creating an autologous AVF, especially in patients with small veins. This technique may provide a better outcome for patients with small cephalic veins.
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The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are emerging tools that can be used in the diagnosis of deep venous thrombosis (DVT). This study aims to evaluate the diagnostic value of NLR and PLR for patients with DVT. Our meta-analysis included 11 eligible studies and extracted relevant diagnostic indicators. Of these studies, 4 focused on the NLR, 1 on the PLR, while 6 evaluated both. For the 10 studies on NLR, the pooled sensitivity, specificity, positive-likelihood ratio, and negative-likelihood ratio were 74%, 66%, 2.16, and 0.4, respectively. The estimated diagnostic odds ratio (DOR) was 5.3, and the area under the curve (AUC) of the summary receiver operating characteristic (SROC) curves was 0.74. For the 7 studies on the PLR, the pooled sensitivity, specificity, positive-likelihood ratio, and negative-likelihood ratio were 0.65, 0.77, 2.89, and 0.45, respectively. The estimated DOR was 6.64, and the SROC-AUC was 0.79. Our findings showed that the NLR and PLR exhibit moderate diagnostic accuracy and may be helpful biomarkers for the diagnosis of DVT. Future prospective, well-designed studies with large sample sizes will be required to provide additional evidence to establish cutoff values and clinical value of these indicators.
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Neutrófilos , Trombose Venosa , Humanos , Linfócitos , Plaquetas , Biomarcadores , Curva ROC , Trombose Venosa/diagnóstico , Estudos RetrospectivosRESUMO
Layered transition metal dichalcogenides (TMDs) are two-dimensional materials exhibiting a variety of unique features with great potential for electronic and optoelectronic applications. The performance of devices fabricated with mono or few-layer TMD materials, nevertheless, is significantly affected by surface defects in the TMD materials. Recent efforts have been focused on delicate control of growth conditions to reduce the defect density, whereas the preparation of a defect-free surface remains challenging. Here, we show a counterintuitive approach to decrease surface defects on layered TMDs: a two-step process including Ar ion bombardment and subsequent annealing. With this approach, the defects, mainly Te vacancies, on the as-cleaved PtTe2 and PdTe2 surfaces were decreased by more than 99%, giving a defect density <1.0 × 1010 cm-2, which cannot be achieved solely with annealing. We also attempt to propose a mechanism behind the processes.
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In this work, the ferroelectric characteristic of a 5 nm Hf0.5Zr0.5O2 (HZO) metal-ferroelectric-insulator-semiconductor (MFIS) device is enhanced through strained complementary metal oxide semiconductor (CMOS)-compatible TiN electrode engineering. Strained TiN top-layer electrodes with different nitrogen (N) concentrations are deposited by adjusting the sputtering process conditions. The TiN electrode with 18% N exhibits a compressive characteristic, which induces tensile stress in a 5 nm HZO film. A device with 18% N in TiN shows a higher remanent polarization (2Pr) and larger capacitance value than the compared sample, indicating that the strained TiN is promising for enhancing the ferroelectricity of sub-5 nm HZO devices.
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Indoor environmental control is usually applied in poultry farming to ensure optimum growth conditions for birds. However, these control methods represent a considerable share of total energy consumption, and the trend of applying new equipment in the future for precision livestock farming would further increase energy demand, resulting in an increase in greenhouse gas emissions and management costs. Therefore, to ensure optimum efficiency of both energy use and livestock productivity, a customized hourly model was developed in the present study to interpret and analyze the electronically collected data. The modules for estimating indoor gas concentrations were incorporated into the present model, as this has not been properly considered in previous studies. A validation test was performed in a manure-belt layer house using sensors and meters to measure the indoor environmental parameters and energy consumption. The predicted results, including indoor temperature, relative humidity, carbon dioxide and ammonia concentrations, showed good agreement with the measured data, indicating a similar overall trend with acceptable discrepancies. Moreover, the corresponding differences between the measured and simulated energy consumption for heating, tunnel ventilation and base ventilation were 13.7, 7.5, and 0.1%, respectively. The total energy demand estimated by the model showed a limited discrepancy of approximately 10.6% compared with that measured in reality. Although human factors, including inspection, cleaning, vaccination, etc., were not included in the model, the validation results still suggested that the customized model was able to accurately predict the indoor environment and overall energy consumption during poultry farming. The validated model provides a tool for poultry producers to optimize production planning and management strategies, increase the production rate of unit energy consumption and achieve precision livestock farming from an energy consumption standpoint.
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Studies have shown that prebiotics can affect meat quality; however, the underlying mechanisms remain poorly understood. This study aimed to investigate whether prebiotics affect the flavor of chicken meat via the gut microbiome and metabolome. The gut content was collected from chickens fed with or without prebiotics (galacto-oligosaccharides or xylo-oligosaccharides) and subjected to microbiome and metabolome analyses, whereas transcriptome sequencing was performed using chicken breast. Prebiotic supplementation yielded a slight improvement that was not statistically significant in the growth and production performance of chickens. Moreover, treatment with prebiotics promoted fat synthesis and starch hydrolysis, thus increasing meat flavor by enhancing lipase and α-amylase activity in the blood of broiler chickens. The prebiotics altered the proportions of microbiota in the gut at different levels, especially microbiota in the phyla Bacteroidetes and Firmicutes, such as members of the Alistipes, Bacteroides, and Faecalibacterium genera. Furthermore, the prebiotics altered the content of cecal metabolites related to flavor substances, including 8 types of lysophosphatidylcholine (lysoPC) and 4 types of amino acid. Differentially expressed genes (DEGs) induced by prebiotics were significantly involved in fatty acid accumulation processes, such as lipolysis in adipocytes and the adipocytokine signaling pathway. Changes in gut microbiota were correlated with metabolites, for example, Bacteroidetes and Firmicutes were positively and negatively correlated with lysoPC, respectively. Finally, DEGs interacted with cecal metabolites, especially meat-flavor-related amino acids and their derivatives. The findings of this study integrated and incorporated associations among the gut microbiota, metabolites, and transcriptome, which suggests that prebiotics affect the flavor of chicken meat.
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Galinhas , Microbiota , Animais , Galinhas/metabolismo , Transcriptoma , Oligossacarídeos/metabolismo , Metaboloma , Carne/análise , Prebióticos/análiseRESUMO
The main advantage of having livestock, for example, the laying hens, in a controlled environment is that the optimum growth conditions can be achieved with accuracy. The indoor air temperature, humidity, gases concentration, etc., would significantly affect the animal performance, thus should be maintained within an acceptable range. In order to achieve the goals of precision poultry farming, various models have been developed by researchers all over the world to estimate the hourly indoor environmental parameters so as to provide decision suggestions. However, a key parameter of hourly manure area in the poultry house was missing in the literature to predict the ammonia emission using the recently developed mechanistic model. Therefore, in order to fill the gap of the understanding of hourly manure coverage proportion and area on the manure belt, experimental measurements were performed in the present study using laying hens from 10 weeks age to 30 weeks age. For each test, six polypropylene (pp) plates were applied to collect the manure dropped by the birds every hour, and photographs of the plates were taken at the same time using a pre-fixed camera. Binary images were then produced based on the color pictures to determine the object coverage proportion. It was demonstrated that for laying hens of stocking density around 14 birds/m2, the manure coverage proportion at the 24th hour after the most recent manure removal was about 60%, while the value was approximately 82% at the 48th hour. Meanwhile, for laying hens at different ages, the hourly increment of manure coverage proportion showed a similar pattern with four distinct stages within 48 h. The statistical analyses demonstrated no significant correlation between the hourly increment of manure weight and the hourly increment of manure coverage proportion. Finally, prediction models for estimating the hourly manure coverage proportion on the manure belt in typical laying hen houses were provided.