Accurately computing the electronic properties of a quantum ring.

A promising approach to study condensed-matter systems is to simulate them on an engineered quantum platform1-4. However, the accuracy needed to outperform classical methods has not been achieved so far. Here, using 18 superconducting qubits, we provide an experimental blueprint for an accurate condensed-matter simulator and demonstrate how to investigate fundamental electronic properties. We benchmark the underlying method by reconstructing the single-particle band structure of a one-dimensional wire. We demonstrate nearly complete mitigation of decoherence and readout errors, and measure the energy eigenvalues of this wire with an error of approximately 0.01 rad, whereas typical energy scales are of the order of 1 rad. Insight into the fidelity of this algorithm is gained by highlighting the robust properties of a Fourier transform, including the ability to resolve eigenenergies with a statistical uncertainty of 10-4 rad. We also synthesize magnetic flux and disordered local potentials, which are two key tenets of a condensed-matter system. When sweeping the magnetic flux we observe avoided level crossings in the spectrum, providing a detailed fingerprint of the spatial distribution of local disorder. By combining these methods we reconstruct electronic properties of the eigenstates, observing persistent currents and a strong suppression of conductance with added disorder. Our work describes an accurate method for quantum simulation5,6 and paves the way to study new quantum materials with superconducting qubits.

Dietary supplementation of vitamin D3 and calcium partially recover the compromised time budget and circadian rhythm of lying behavior in lactating cows under heat stress.

Heat stress (HS) impedes cattle behavior and performance and is an animal comfort and welfare issue. The objective of this study was to characterize the time budget and circadian rhythm of lying behavior in dairy cows during HS and to assess the effect of dietary supplementation of vitamin D3 and Ca. Twelve multiparous Holstein cows (42.2 ± 5.6 kg milk/d; 83 ± 27 d in milk) housed in tiestalls were used in a split-plot design with the concentration of dietary vitamin E and Se as main plots (LESe: 11.1 IU/kg and 0.55 mg/kg, and HESe: 223 IU/kg and 1.8 mg/kg, respectively). Within each plot cows were randomly assigned to (1) HS with low concentrations of vitamin D3 and Ca (HS, 1,012 IU/kg and 0.73%, respectively), (2) HS with high concentrations of vitamin D3 and Ca (HS+D3/Ca; 3,764 IU/kg and 0.97%, respectively), or (3) thermoneutral pair-fed (TNPF) with low concentrations of vitamin D3 and Ca (1,012 IU/kg and 0.73%, respectively) in a Latin square design with 14-d periods and 7-d washouts. Lying behavior was measured with HOBO Loggers in 15-min intervals. Overall, cows in HS spent less time lying per day relative to TNPF from d 7 to 14. Daily lying time was positively correlated with milk yield, energy-corrected milk yield, and feed efficiency, and was negatively correlated with rectal temperature, respiratory rate, fecal calprotectin, tumor necrosis factor-α, and C-reactive protein. A treatment by time interaction was observed for lying behavior: the time spent lying was lesser for cows in HS than in TNPF in the early morning (0000-0600 h) and in the night (1800-2400 h). The circadian rhythm of lying behavior was characterized by fitting a cosine function of time into linear mixed model. Daily rhythmicity of lying was detected for cows in TNPF and HS+D3/Ca, whereas only a tendency in HS cows was observed. Cows in TNPF had the highest mesor (the average level of diurnal fluctuations; 34.2 min/h) and amplitude (the distance between the peak and mesor; 17.9 min/h). Both the mesor and amplitude were higher in HS+D3/Ca relative to HS (26.6 vs. 25.2 min/h and 3.91 min/h vs. 2.18 min/h, respectively). The acrophase (time of the peak) of lying time in TNPF, HS, and HS+D3/Ca were 0028, 0152, and 0054 h, respectively. Lastly, a continuous increase in daily lying time in TNPF was observed during the first 4 d of the experimental period in which DMI was gradually restricted, suggesting that intake restrictions may shift feeding behavior and introduce biases in the behavior of animals. In conclusion, lying behavior was compromised in dairy cows under HS, characterizing reduced daily lying time and disrupted circadian rhythms, and the compromised lying behavior can be partially restored by supplementation of vitamin D3 and Ca. Further research may be required for a more suitable model to study behavior of cows under HS.

Exhalomics as a noninvasive method for assessing rumen fermentation in dairy cows: Can exhaled-breath metabolomics replace rumen sampling?

Previously, we used secondary electrospray ionization-mass spectrometry (SESI-MS) to investigate the diurnal patterns and signal intensities of exhaled (EX) volatile fatty acids (VFA) of dairy cows. The current study aimed to validate the potential of an exhalomics approach for evaluating rumen fermentation. The experiment was conducted in a switchback design, with 3 periods of 9 d each, including 7 d for adaptation and 2 d for sampling. Four rumen-cannulated original Swiss Brown (Braunvieh) cows were randomly assigned to 1 of 2 diet sequences (ABA or BAB): (A) low starch (LS; 6.31% starch on a dry matter basis) and (B) high starch (HS; 16.2% starch on a dry matter basis). Feeding was once per day at 0830 h. Exhalome (with the GreenFeed System), and rumen samples were collected 8 times to represent every 3 h of a day, and EX-VFA and ruminal (RM)-VFA were analyzed using SESI-MS and HPLC, respectively. Furthermore, the VFA concentration in the gas phase (HR-VFA) was predicted based on RM-VFA and Henry's Law (HR) constants. No interactions were identified between the types of diets (HS vs. LS) and the measurement methods on daily average VFA profiles (RM vs. EX or HR vs. EX), suggesting a consistent performance among the methods. Additionally, when the 3-h interval VFA data from HS and LS diets were analyzed separately, no interactions were observed between methods and time of day, indicating that the relative daily pattern of VFA molar proportions was similar regardless of the VFA measurement method used. The results revealed that the levels of acetate sharply increased immediately after feeding, trailed by an increase in the acetate:propionate ratio and a steady increase for propionate (2 h after feeding the HS diet, 4 h for LS), and butyrate. This change was more pronounced for the HS diet than the LS diet. However, there was no overall diet effect on the VFA molar proportions, although the measurement methods affected the molar proportions. Furthermore, we observed a strong positive correlation between the levels of RM and EX acetate for both diets (HS: r = 0.84; LS: r = 0.85), RM and EX propionate (r = 0.74), and RM and EX acetate:propionate ratio (r = 0.80). Both EX-VFA and RM-VFA exhibited similar responses to feeding and dietary treatments, suggesting that EX-VFA could serve as a useful proxy for characterizing RM-VFA molar proportions to evaluate rumen fermentation. Similar relationships were observed between RM-VFA and HR-VFA. In conclusion, this study underscores the potential of exhalomics as a reliable approach for assessing rumen fermentation. Moving forward, research should further explore the depth of exhalomics in ruminant studies to provide a comprehensive insight into rumen fermentation metabolites, especially across diverse dietary conditions.

Effects of 3-nitrooxypropanol (3-NOP, Bovaer®10) and whole cottonseed on milk production and enteric methane emissions from dairy cows under Swiss management conditions.

The objective of this study was to determine the potential effect and interaction of 3- nitrooxypropanol (3-NOP; Bovaer®) and whole cottonseed (WCS) on lactational performance, and enteric methane (CH4) emission of dairy cows. A total of 16 multiparous cows, including 8 Holstein Friesian (HF) and 8 Brown Swiss (BS) [224 ± 36 d in milk, 26 ± 3.7 kg milk yield], were used in a split-plot design, where the main plot was the breed of cows. Within each subplot, cows were randomly assigned to a treatment sequence in a replicated 4 × 4 Latin Square design with 2 × 2 factorial arrangements of treatments with 4, 24-d periods. The experimental treatments were: 1) Control (basal TMR), 2) 3-NOP (60 mg/kg TMR DM), 3) WCS (5% TMR DM), and 4) 3-NOP + WCS. The treatment diets were balanced for ether extract, crude protein, and NDF contents (4%, 16%, and 43% of TMR DM, respectively). The basal diets were fed twice daily at 0800 and 1800 h. Dry matter intake (DMI) and milk yield were measured daily, and enteric gas emissions were measured (using the GreenFeed system) during the last 3 d of each 24-d experimental period when animals were housed in tie stalls. There was no difference in DMI on treatment level, whereas the WCS treatment increased ECM yield and milk fat yield. There was no interaction of 3-NOP and WCS for any of the enteric gas emission parameters, but 3-NOP decreased CH4 production (g/d), CH4 yield (g/kg DMI), and CH4 intensity (g/kg ECM) by 13, 14 and 13%, respectively. Further, an unexpected interaction of breed by 3-NOP was observed for different enteric CH4 emission metrics: HF cows had a greater CH4 mitigation effect compared with BS cows for CH4 production (g/d; 18 vs. 8%), CH4 intensity (g/kg MY; 19% vs. 3%) and CH4 intensity (g/kg ECM; 19 vs. 4%). Hydrogen production was increased by 2.85 folds in HF and 1.53 folds in BS cows receiving 3-NOP. Further, there was a 3-NOP ' Time interaction for both breeds. In BS cows, 3-NOP tended to reduce CH4 production by 18% at around 4 h after morning feeding but no effect was observed at other time points. In HF cows, the greatest mitigation effect of 3-NOP (29.6%) was observed immediately after morning feeding and it persisted at around 23% to 26% for 10 h until the second feed provision, and 3 h thereafter, in the evening. In conclusion, supplementing 3-NOP at 60 mg/kg DM to a high fiber diet resulted in 18 to 19% reduction in enteric CH4 emission in Swiss Holstein Friesian cows. The lower response to 3-NOP by BS cows was unexpected and has not been observed in other studies. These results should be interpreted with caution due to low number of cows per breed. Lastly, supplementing WCS at 5% of DM improved ECM and milk fat yield but did not enhance CH4 inhibition effect of 3-NOP of dairy cows.

[HVPG minimally invasive era: exploration based on forearm venous approach].

Objective: The transjugular or transfemoral approach is used as a common method for hepatic venous pressure gradient (HVPG) measurement in current practice. This study aims to confirm the safety and effectiveness of measuring HVPG via the forearm venous approach. Methods: Prospective recruitment was conducted for patients with cirrhosis who underwent HVPG measurement via the forearm venous approach at six hospitals in China and Japan from September 2020 to December 2020. Patients' clinical baseline information and HVPG measurement data were collected. The right median cubital vein or basilic vein approach for all enrolled patients was selected. The HVPG standard process was used to measure pressure. Research data were analyzed using SPSS 22.0 statistical software. Quantitative data were used to represent medians (interquartile ranges), while qualitative data were used to represent frequency and rates. The correlation between two sets of data was analyzed using Pearson correlation analysis. Results: A total of 43 cases were enrolled in this study. Of these, 41 (95.3%) successfully underwent HVPG measurement via the forearm venous approach. None of the patients had any serious complications. The median operation time for HVPG detection via forearm vein was 18.0 minutes (12.3~38.8 minutes). This study confirmed that HVPG was positively closely related to Child-Pugh score (r = 0.47, P = 0.002), albumin-bilirubin score (r = 0.37, P = 0.001), Lok index (r = 0.36, P = 0.02), liver stiffness (r = 0.58, P = 0.01), and spleen stiffness (r = 0.77, P = 0.01), while negatively correlated with albumin (r = -0.42, P = 0.006). Conclusion: The results of this multi-centre retrospective study suggest that HVPG measurement via the forearm venous approach is safe and feasible.

Exhaled volatile fatty acids, ruminal methane emission, and their diurnal patterns in lactating dairy cows.

To date, the commonly used methods to assess rumen fermentation are invasive. Exhaled breath contains hundreds of volatile organic compounds (VOC) that can reflect animal physiological processes. In the present study, for the first time, we aimed to use a noninvasive metabolomics approach based on high-resolution mass spectrometry to identify rumen fermentation parameters in dairy cows. Enteric methane (CH4) production from 7 lactating cows was measured 8 times over 3 consecutive days using the GreenFeed system (C-Lock Technology Inc.). Simultaneously, exhalome samples were collected in Tedlar gas sampling bags and analyzed offline using a secondary electrospray ionization high-resolution mass spectrometry system. In total, 1,298 features were detected, among them targeted exhaled volatile fatty acids (eVFA; i.e., acetate, propionate, butyrate), which were putatively annotated using their exact mass-to-charge ratio. The intensity of eVFA, in particular acetate, increased immediately after feeding and followed a similar pattern to that observed for ruminal CH4 production. The average total eVFA concentration was 35.5 count per second (CPS), and among the individual eVFA, acetate had the greatest concentration, averaging 21.3 CPS, followed by propionate at 11.5 CPS, and butyrate at 2.67 CPS. Further, exhaled acetate was on average the most abundant of the individual eVFA at around 59.3%, followed by 32.5 and 7.9% of the total eVFA for propionate and butyrate, respectively. This corresponds well with the previously reported proportions of these VFA in the rumen. The diurnal patterns of ruminal CH4 emission and individual eVFA were characterized using a linear mixed model with cosine function fit. The model characterized similar diurnal patterns for eVFA and ruminal CH4 and H2 production. Regarding the diurnal patterns of eVFA, the phase (time of peak) of butyrate occurred first, followed by that of acetate and propionate. Importantly, the phase of total eVFA occurred around 1 h before that of ruminal CH4. This corresponds well with existing data on the relationship between rumen VFA production and CH4 formation. Results from the present study revealed a great potential to assess the rumen fermentation of dairy cows using exhaled metabolites as a noninvasive proxy for rumen VFA. Further validation, with comparisons to rumen fluid, and establishment of the proposed method are required.

Prediction of nitrogen excretion from data on dairy cows fed a wide range of diets compiled in an intercontinental database: A meta-analysis.

Manure nitrogen (N) from cattle contributes to nitrous oxide and ammonia emissions and nitrate leaching. Measurement of manure N outputs on dairy farms is laborious, expensive, and impractical at large scales; therefore, models are needed to predict N excreted in urine and feces. Building robust prediction models requires extensive data from animals under different management systems worldwide. Thus, the study objectives were (1) to collate an international database of N excretion in feces and urine based on individual lactating dairy cow data from different continents; (2) to determine the suitability of key variables for predicting fecal, urinary, and total manure N excretion; and (3) to develop robust and reliable N excretion prediction models based on individual data from lactating dairy cows consuming various diets. A raw data set was created based on 5,483 individual cow observations, with 5,420 fecal N excretion and 3,621 urine N excretion measurements collected from 162 in vivo experiments conducted by 22 research institutes mostly located in Europe (n = 14) and North America (n = 5). A sequential approach was taken in developing models with increasing complexity by incrementally adding variables that had a significant individual effect on fecal, urinary, or total manure N excretion. Nitrogen excretion was predicted by fitting linear mixed models including experiment as a random effect. Simple models requiring dry matter intake (DMI) or N intake performed better for predicting fecal N excretion than simple models using diet nutrient composition or milk performance parameters. Simple models based on N intake performed better for urinary and total manure N excretion than those based on DMI, but simple models using milk urea N (MUN) and N intake performed even better for urinary N excretion. The full model predicting fecal N excretion had similar performance to simple models based on DMI but included several independent variables (DMI, diet crude protein content, diet neutral detergent fiber content, milk protein), depending on the location, and had root mean square prediction errors as a fraction of the observed mean values of 19.1% for intercontinental, 19.8% for European, and 17.7% for North American data sets. Complex total manure N excretion models based on N intake and MUN led to prediction errors of about 13.0% to 14.0%, which were comparable to models based on N intake alone. Intercepts and slopes of variables in optimal prediction equations developed on intercontinental, European, and North American bases differed from each other, and therefore region-specific models are preferred to predict N excretion. In conclusion, region-specific models that include information on DMI or N intake and MUN are required for good prediction of fecal, urinary, and total manure N excretion. In absence of intake data, region-specific complex equations using easily and routinely measured variables to predict fecal, urinary, or total manure N excretion may be used, but these equations have lower performance than equations based on intake.

[Status of HVPG clinical application in China in 2021].

Objective: The investigation and research on the application status of Hepatic Venous Pressure Gradient (HVPG) is very important to understand the real situation and future development of this technology in China. Methods: This study comprehensively investigated the basic situation of HVPG technology in China, including hospital distribution, hospital level, annual number of cases, catheters used, average cost, indications and existing problems. Results: According to the survey, there were 70 hospitals in China carrying out HVPG technology in 2021, distributed in 28 provinces (autonomous regions and municipalities directly under the central Government). A total of 4 398 cases of HVPG were performed in all the surveyed hospitals in 2021, of which 2 291 cases (52.1%) were tested by HVPG alone. The average cost of HVPG detection was (5 617.2±2 079.4) yuan. 96.3% of the teams completed HVPG detection with balloon method, and most of the teams used thrombectomy balloon catheter (80.3%). Conclusion: Through this investigation, the status of domestic clinical application of HVPG has been clarified, and it has been confirmed that many domestic medical institutions have mastered this technology, but it still needs to continue to promote and popularize HVPG technology in the future.

Diffusion-tensor imaging for differentiating uterine sarcoma from degenerative uterine fibroids.

AIM: To explore the applicability of diffusion-tensor imaging (DTI) sequence quantitative parameters in differentiating uterine sarcoma (USr) from degenerative uterine fibroids (DUF). MATERIALS AND METHODS: Fourteen cases of USr and 30 cases of DUF were analysed retrospectively. The diffusion-weighted imaging (DWI) and DTI images were analysed by two observers using Functool software on a ADW4.6 workstation. The images were post-processed to generate an apparent diffusion coefficient (ADC) map of DWI, ADC map of DTI (ADCT map), and fractional anisotropy (FA) map. Three regions of interest (ROI) were selected from the ADC, ADCT, and FA maps to obtain the ADC, ADCT, and FA values. The receiver operating characteristic (ROC) curves of all parameters were used to analyse and compare the diagnostic value of USr and DUF. RESULTS: The ADC value, ADCT value, and FA value of USr (1.190 ± 0.262 × 10-3mm2/s, 1.165 ± 0.270 × 10-9mm2/s, 0.168 ± 0.063) were significantly lower compared to the values for DUF (1.525 ± 0.314 × 10-3mm2/s, 1.650 ± 0.332 × 10-9mm2/s, 0.254 ± 0.111; all p<0.001). The diagnostic threshold values for USr were: ADC ≤1.290 × 10-3mm2/s, ADCT ≤1.322 × 10-9mm2/s and FA ≤0.192. The corresponding sensitivities and specificities were 78.6%/90%, 96.7%/92.9%, and 86.7%/85.7%, respectively. The areas under the curve (AUC) were 0.875, 0.974, and 0.831, respectively. CONCLUSIONS: DTI quantitative parameters can be used to differentiate USr from DUF. The ADCT value had the highest diagnostic efficacy.

Demonstrating a Continuous Set of Two-Qubit Gates for Near-Term Quantum Algorithms.

Quantum algorithms offer a dramatic speedup for computational problems in material science and chemistry. However, any near-term realizations of these algorithms will need to be optimized to fit within the finite resources offered by existing noisy hardware. Here, taking advantage of the adjustable coupling of gmon qubits, we demonstrate a continuous two-qubit gate set that can provide a threefold reduction in circuit depth as compared to a standard decomposition. We implement two gate families: an imaginary swap-like (iSWAP-like) gate to attain an arbitrary swap angle, θ, and a controlled-phase gate that generates an arbitrary conditional phase, ϕ. Using one of each of these gates, we can perform an arbitrary two-qubit gate within the excitation-preserving subspace allowing for a complete implementation of the so-called Fermionic simulation (fSim) gate set. We benchmark the fidelity of the iSWAP-like and controlled-phase gate families as well as 525 other fSim gates spread evenly across the entire fSim(θ,ϕ) parameter space, achieving a purity-limited average two-qubit Pauli error of 3.8×10^{-3} per fSim gate.

A longitudinal study on α-synuclein in plasma neuronal exosomes as a biomarker for Parkinson's disease development and progression.

BACKGROUND AND PURPOSE: The identification of reliable diagnostic and prognostic biomarkers for Parkinson's disease (PD) is urgently needed. Here, we explored the potential use of α-synuclein (α-syn) in plasma neuronal exosomes as a biomarker for early PD diagnosis and disease progression. METHODS: This study included both cross-sectional and longitudinal designs. The subjects included 36 patients with early-stage PD, 17 patients with advanced PD, 20 patients with idiopathic rapid eye movement sleep behavior disorder and 21 healthy controls (HCs). α-syn levels were measured by electrochemiluminescence immunoassay. A subgroup of patients with early-stage PD (n = 18) participated in a follow-up examination with repeated blood collection and clinical assessments after an average of 22 months. RESULTS: The α-syn levels in plasma neuronal exosomes were significantly higher in patients with early-stage PD compared with HCs (P = 0.007). Differences in α-syn levels between patients with idiopathic rapid eye movement sleep behavior disorder and HCs did not reach statistical significance (P = 0.08). In addition, Spearman correlation analysis revealed that neuronal exosomal α-syn concentrations were correlated with Movement Disorders Society Unified Parkinson's Disease Rating Scale III/(I + II + III) scores, Non-Motor Symptom Questionnaire scores and Sniffin' Sticks 16-item test scores of patients with PD (P < 0.05). After a mean follow-up of 22 months in patients with early-stage PD, a Cox regression analysis adjusted for age and gender showed that longitudinally increased α-syn rather than baseline α-syn levels were associated with higher risk for motor symptom progression in PD (P = 0.039). CONCLUSIONS: Our results suggested that α-syn in plasma neuronal exosomes may serve as a biomarker to aid early diagnosis of PD and also as a prognostic marker for PD progression.

[The clinical characteristic treatment strategy and prognosis of adenoid cystic carcinoma of the head and neck].

Objective: To explore the clinical characteristics, treatment strategy and prognosis of adenoid cystic carcinoma of the head and neck (ACCHN). Methods: A retrospective analysis of the clinical and follow-up treatment of 79 patients with ACCHN from June 2008 to July 2017 was conducted in the Cancer Hospital of Zhengzhou University. Results: A total of 79 ACCHN cases, including 31 males and 48 females. The age ranged from 19 to 77 (median, 52). The clinical manifestations of ACC were related to the locations of primary tumor.The mean size of the tumor was 2.6 cm (range from 1.5 to 7.7 cm). 50 of 79 patients with a definitive pathological diagnosis received surgical resection. 59 cases received chemotherapy and 62 cases received radiotherapy. With a median follow-up of 55 months, the 5-year, 10-year survival rate of these patients were 69.6% and 54.4%, respectively. Conclusions: ACCHN is an uncommon neoplasm with the characteristics of epithelial nerve growth, being inclined to distant metastasis, and high early misdiagnosis rate. The clinical manifestation, imaging and pathological result are need to be combined together to diagnose ACCHN.

Dissociation Energy of the Hydrogen Molecule at 10

The ionization energy of ortho-H_{2} has been determined to be E_{I}^{o}(H_{2})/(hc)=124 357.238 062(25) cm^{-1} from measurements of the GK(1,1)-X(0,1) interval by Doppler-free, two-photon spectroscopy using a narrow band 179-nm laser source and the ionization energy of the GK(1,1) state by continuous-wave, near-infrared laser spectroscopy. E_{I}^{o}(H_{2}) was used to derive the dissociation energy of H_{2}, D_{0}^{N=1}(H_{2}), at 35 999.582 894(25) cm^{-1} with a precision that is more than one order of magnitude better than all previous results. The new result challenges calculations of this quantity and represents a benchmark value for future relativistic and QED calculations of molecular energies.

Short communication: The effects of morning compared with evening feed delivery in lactating dairy cows during the summer.

Delivering fresh feed in the evening is a management strategy sometimes used during periods of heat stress, but previous experiments have observed that night feeding increased feed intake during the 2 h after feeding and did not change intake during the overnight period. The objective of this study was to determine the effect of night feeding on daily rhythms of the dairy cow during the summer season. Twelve Holstein cows were used in a crossover design with 14-d periods. An automated system recorded the timing of feed intake over the last 7 d of each period. Treatments were ad libitum feeding with fresh feed delivery 1×/d at 0830 h or 2030 h. Milk yield and composition were not changed by treatment, but night feeding decreased the concentration of preformed fatty acids in milk fat. Night feeding decreased feed intake 1.7 kg/d, and decreased total-tract dry matter and neutral detergent fiber (NDF) digestibility by 0.7 and 0.8 percentage units, respectively. The amount of feed consumed in the first 2 h after feeding was 64% greater with night feeding, but intake did not differ between treatments during the night or early afternoon. A treatment by time of day interaction was observed for fecal NDF and indigestible NDF concentration and plasma glucose, insulin, and urea concentrations. Night feeding resulted in an increase in plasma insulin after feeding, which decreased plasma glucose. The daily rhythm of core body temperature was entrained by treatment, with the phase shifted and the amplitude decreased by night feeding indicating alteration of the central clock. In conclusion, feeding cows once per day in the evening during the summer caused a similar increase in feed intake and plasma insulin after feeding as previously observed during non-heat stress seasons. Night feeding also decreased intake and total-tract digestibility. The daily pattern of feed intake and other behaviors should be considered before initiation of night feeding.

The effects of feeding a partial mixed ration plus a top-dress before feeding on milk production and the daily rhythm of feed intake and plasma hormones and metabolites in dairy cows.

Total mixed rations (TMR) are commonly fed to dairy cows with a goal of reducing ruminal acidosis, but the daily pattern of feed intake has major implication for rumen fermentation and postabsorptive physiology. Generally there is low feed intake during the overnight period and high intake after feeding and during the afternoon. The objective of this study was to determine if feeding a partial mixed ration (PMR) plus a high starch top-dress before feeding of the PMR would improve production and modify key daily rhythms. The top-dress was fed before feeding as ruminal starch is at a nadir and amylolytic capacity is expected to be low. Ten Holstein cows were used in a crossover design with 14-d periods. Cows were housed in tie stalls with feed tubs and feed weight was recorded every 10 s for observation of feeding behavior. Treatments were a control TMR fed once per day at 0900 h or a partial mixed ration plus a top-dress (PMR+TD). The top-dress was fed at 9.5% of DMI offered at 0800 h and contained steamflaked corn, canola meal, and nonprotein nitrogen. No interaction was observed between treatment and milking time. Milk yield tended to be decreased 1.1 kg and milk fat yield was decreased 70 g/d by PMR+TD. Milk fat preformed fatty acids were decreased and no effect was observed of treatment on trans-10 C18:1 or other indicators of biohydrogenation-induced milk fat depression. No effect was observed of treatment on meal parameters including meal size and number. The PMR+TD increased total-tract neutral detergent fiber (NDF) digestibility by 1.2 percentage points. Treatment changed the daily pattern of fecal NDF and indigestible NDF, indicating changes in rumen function over the day. No effect was observed on plasma glucose, but the amplitude of the daily rhythm of insulin was increased by PMR+TD. The PMR+TD also increased plasma nonesterified fatty acids and decreased blood urea nitrogen across the day. Core body temperature is entrained by the central biological clock and its phase was advanced 42 min and its amplitude slightly increased by PMR+TD. In conclusion, the top-dress appears to have modified the central circadian rhythm and plasma insulin and blood urea nitrogen. This demonstrates that timing of feeding can be used to manage daily rhythms of the dairy cow, although the optimal timing requires further investigation.

Symposium review: Uncertainties in enteric methane inventories, measurement techniques, and prediction models.

Ruminant production systems are important contributors to anthropogenic methane (CH4) emissions, but there are large uncertainties in national and global livestock CH4 inventories. Sources of uncertainty in enteric CH4 emissions include animal inventories, feed dry matter intake (DMI), ingredient and chemical composition of the diets, and CH4 emission factors. There is also significant uncertainty associated with enteric CH4 measurements. The most widely used techniques are respiration chambers, the sulfur hexafluoride (SF6) tracer technique, and the automated head-chamber system (GreenFeed; C-Lock Inc., Rapid City, SD). All 3 methods have been successfully used in a large number of experiments with dairy or beef cattle in various environmental conditions, although studies that compare techniques have reported inconsistent results. Although different types of models have been developed to predict enteric CH4 emissions, relatively simple empirical (statistical) models have been commonly used for inventory purposes because of their broad applicability and ease of use compared with more detailed empirical and process-based mechanistic models. However, extant empirical models used to predict enteric CH4 emissions suffer from narrow spatial focus, limited observations, and limitations of the statistical technique used. Therefore, prediction models must be developed from robust data sets that can only be generated through collaboration of scientists across the world. To achieve high prediction accuracy, these data sets should encompass a wide range of diets and production systems within regions and globally. Overall, enteric CH4 prediction models are based on various animal or feed characteristic inputs but are dominated by DMI in one form or another. As a result, accurate prediction of DMI is essential for accurate prediction of livestock CH4 emissions. Analysis of a large data set of individual dairy cattle data showed that simplified enteric CH4 prediction models based on DMI alone or DMI and limited feed- or animal-related inputs can predict average CH4 emission with a similar accuracy to more complex empirical models. These simplified models can be reliably used for emission inventory purposes.

Effect of Dairy Manure Storage Conditions on the Survival of E. coli O157:H7 and Listeria.

Dairy manure is regularly applied to crop fields as a solid or liquid to improve the soil nutrient status. However, pathogens may survive during manure storage and enter the environment during application. In this study, three storage practices were evaluated to understand the survival patterns of O157:H7 and spp. in dairy manure using a culture-based approach. To replicate common farm manure storage techniques, solid manure was stacked as piles with periodic turning or as static piles without turning, whereas liquid manure (feces, urine, and water) was stored as a slurry in small tanks to simulate lagoon conditions. The and levels in the manure samples were determined for 29 wk. Results showed that there was an initial reduction in bacteria levels in the first month; however, both and managed to survive in the solid manure piles for the full study period. In slurry samples, was not detected after 14 wk, but survived until the end of the experiment at relatively lower levels than in the solid manure piles. Ambient weather and pile size were identified as the main reasons for bacteria survival during the course of the experiment. The outcome of this study is important in terms of understanding pathogen survival in manure piles and slurries prior to their application to crop fields.

[Prevalence and risk factors of diabetic retinopathy in hospital patients].

Objective: To analyze the prevalence and risk factors of diabetic retinopathy (DR) in ophthalmic patients. Methods: A cross-sectional study was performed. Diabetic patients who were admitted to Department of Ophthalmology, Traditional Chinese Medicine Hospital of Muping between October 2012 and June 2013 were included. General information and medical history were obtained from each subject by questionaires. Laboratory and detailed ophthalmic examinations were performed during the study. DR was diagnosed and graded by mydriatic fundus photography. Prevalence of DR was calculated and logistic regression was used to analyze the relationship between DR and various factors. Results: A total of 676 diabetic patients were included, and 455 of them presented with DR at a morbidity rate of 67.31%. Among DR patients, the number of mild, moderate, severe non-proliferative diabetic retinopathy (NPDR) patients and proliferative diabetic retinopathy (PDR) patients were 211 (46.37%), 167 (36.70%), 57 (12.53%) and 20 (4.40%), respectively. There was no significant difference in the prevalence of DR among different age groups (χ(2)=6.527, P=0.089). However, there was a significant difference between different disease duration groups (χ(2)=39.401, P<0.001), as well as between insulin therapy group and non-insulin therapy group (χ(2)=7.378, P=0.007). The multivariate logistic regression analysis demonstrated the independent risk factors for DR occurrence were hemoglobin A1c (HbA1c) (OR=1.131, 95%CI: 1.022-1.252, P=0.011) and duration of diabetes (OR=1.077, 95%CI: 1.046-1.108, P<0.001). Conclusions: The prevalence of DR in ophthalmic patients was associated with duration of diabetes, HbA1c, obesity, smoke, nephropaty and insulin therapy. Increased HbA1c level and longer duration of diabetes were independent risk factors for DR in diabetic patients.

[Safety and efficacy of transcatheter closure of ruptured sinus of Valsalva aneurysm].

Objective: To investigate the safety and efficacy of transcatheter closure of ruptured sinus of Valsava aneurysm(RSVA). Methods: A total of 33 RSVA patients underwent transcatheter closure from January 2006 to March 2017 in our hospital were included in this retrospective study. The RSVA was diagnosed by echocardiography.Different type of occluders were applied for transcatheter closure based on the aortography results. All the patients were followed up after the procedure. Results: The patients were (37.6±12.1) years old,and the male patients accounted for 78.8%(26 cases).RSVA from right coronary sinus was found in 25 patients,and draining chamber was right atrium in 13 cases, right ventricle in 12 cases. RSVA from noncoronary sinus was diagnosed in 8 patients,and the draining chamber was right atrium. Aortography defined the narrowest diameter at the rupture site was (6.4±1.7)mm. The ratio of Qp/Qs was 2.2±0.5,and the mean pressure of pulmonary artery was 24.0(21.2,33.7)mmHg(1 mmHg=0.133 kPa). One patient developed serious occluder related aortic regurgitation and underwent surgery, transcatheter closure was successfully performed in 32 patients. The success rate of transcatheter closure was 97.0%. Two types of device were used in the study including small-waist double-disk ventricular septal defect(VSD) occluders in 20 cases and patent ductus arteriosus(PDA) occluders in 12 cases. During a median follow-up of 73.5(28.3,89.5) months, there were no infective endocarditis, residual shunt, thrombosis, device displacement,serious aortic regurgitation, serious arrhythmia or death.At the last follow-up, the left atrial diameter((37.4±6.5) mm vs. (41.5±5.3)mm,P<0.01),right atrial diameter((42.4±3.0) mm vs. (48.5±6.0)mm,P<0.01), right ventricular diameter((22.2±3.8) mm vs. (27.7±7.2)mm,P<0.01) and left ventricular end-diastolic diameter((51.3±4.9) mm vs.(55.0±4.3)mm,P<0.01)measured by echocardiography were all smaller than pre-procedural level. Conclusion: Transcatheter closure of RVSA is a safe and effective strategy and associated with a good long-term outcome.

Short communication: Effect of a citrus extract in lactating dairy cows.

Dry matter intake is a main driver of energy balance in lactating dairy cows, and some plant extracts have been commercially fed to dairy cows to stimulate feed intake. Citrus extracts contain several bioactive components and have been shown to modify metabolism in other animal models. Our hypothesis was that a citrus extract would increase dry matter intake. Two experiments were conducted to determine the effect of a citrus extract on intake and milk production in lactating dairy cows. In experiment one, 11 early-lactation dairy cows (experiment 1; 77 ± 15 d in milk, mean ± standard deviation) were used in a switchback design, and in experiment two, 15 mid-lactation Holstein cows (experiment 2; 157 ± 44 d in milk, mean ± standard deviation) were used in a crossover design. In both experiments, treatments were control (no supplement) or a citrus extract (4 g/d in experiment 1 and 4.5 g/d in experiment 2). Treatment periods were 21 and 14 d in experiment 1 and experiment 2, respectively, with the final 7 d used for sample and data collection. No effect was observed for treatment on dry matter intake, feeding behavior, milk yield, milk fat yield, milk protein yield, or milk composition in either experiment. Treatment also had no effect on milk trans fatty acid profile, but the extract increased total 16 carbon fatty acids 0.9 and 0.6 percentage points in experiment 1 and experiment 2, respectively. Plasma nonesterified fatty acids were decreased 6 h after feeding in both experiments (11.1 and 16.0 µEq/L in experiment 1 and experiment 2, respectively). Plasma insulin was increased 1 h before feeding compared with the control in experiment 1 (3.36 vs. 2.13 µIU/mL) and tended to increase 1.79 units 1 h before feeding in experiment 2. The citrus extract had no effect on feed intake or milk production at the dose investigated, but changed plasma insulin and nonesterified fatty acids, indicating some metabolic effects requiring further investigation.