Performance benchmarking of an ultra-low vibration laboratory to host a commercial millikelvin scanning tunnelling microscope.

Ultra-low temperature scanning tunnelling microscopy and spectroscopy (STM/STS) achieved by dilution refrigeration can provide unrivalled insight into the local electronic structure of quantum materials and atomic-scale quantum systems. Effective isolation from mechanical vibration and acoustic noise is critical in order to achieve ultimate spatial and energy resolution. Here, we report on the design and performance of an ultra-low vibration (ULV) laboratory hosting a customized but otherwise commercially available 40 mK STM. The design of the vibration isolation consists of a T-shaped concrete mass block (∼55t), suspended by actively controlled pneumatic springs, and placed on a foundation separated from the surrounding building in a 'room-within-a-room' design. Vibration levels achieved are meeting the VC-M vibration standard at >3 Hz, reached only in a limited number of laboratories worldwide. Measurement of the STM's junction noise confirms effective vibration isolation on par with custom built STMs in ULV laboratories. In this tailored low-vibration environment, the STM achieves an energy resolution of 43µeV (144 mK), promising for the investigation and control of quantum matter at atomic length scales.

Effects of Using Epidural Analgesia during Delivery on Maternal and Infant Outcomes.

OBJECTIVES: The aim of the study was to estimate the impact of epidural analgesia (EA) during delivery on maternal and infant outcomes. DESIGN: This was a prospective cohort study. PARTICIPANTS: In total, 159 pregnant multiparas in Women and Children's Hospital, School of Medicine, Xiamen University from November 2019 to May 2020 were enrolled. Patients were divided into the EA group (n = 80) and no analgesia group (n = 79) based on the choice of the parturients. METHODS: The duration of labor, levels of umbilical arterial blood gas (pH and partial pressure oxygen), visual analog score (VAS), and adverse events were evaluated to compare differences between the EA group and no analgesia group, respectively. RESULTS: The duration of labor was prolonged in the entire labor (p = 0.002), and the first stage (p = 0.001) in the EA group compared with the no analgesia group. The second stage of labor and third stage of labor, levels of umbilical arterial blood gas, and 1-min Apgar score in neonates were similar in EA and no analgesia groups (All p > 0.05). After adjusting age, prepregnancy body mass index, and past and present medical history, the VAS was low in the EA group compared with the no analgesia group when the uterine orifice was completely open (odds ratio [OR] = 0.001, 95% confidence interval [CI]: 0.001-0.002), 8 h postdelivery (OR = 0.508, 95% CI: 0.264-0.977), and 24 h postdelivery (OR = 0.321, 95% CI: 0.167-0.617). EA increased the proportion of adverse events occurring 5 min postdelivery (χ2 = 10.137, p = 0.001), while decreased the proportion of adverse events occurring 24 h postdelivery (χ2 = 4.750, p = 0.029). LIMITATIONS: In terms of the effects of EA on neonates, we only measured the 1-min Apgar score of neonates. CONCLUSIONS: EA might be a reliable pain relief method for pregnant women. The results of our study might give a reference for the use of EA during delivery in clinic.

Time- and dose-dependent correlations between patient-controlled epidural analgesia and intrapartum maternal fever.

BACKGROUND: To investigate the relationship between intrapartum maternal fever and the duration and dosage of patient-controlled epidural analgesia (PCEA). METHODS: This observational study included 159 pregnant women who voluntarily accepted PCEA. During labor, patients with body temperature ≥ 38 °C were classified into the Fever group, (n = 42), and those with body temperature < 38 °C were classified into the No-fever group (n = 117). The outcome measures included the duration of PCEA, number of PCEA, and total PCEA amount. Body temperature and parturient variables, including interpartum fever status and the duration of any fever were monitored. RESULTS: The total PCEA duration and total PCEA amount in the Fever group were significantly higher than the corresponding values in the No-fever group (both, p < 0.05). The duration of fever was weakly correlated with the duration of PCEA (R2 = 0.08) and the total PCEA amount (R2 = 0.05) (both, p < 0.05). The total and effective PCEA were higher in the Fever group than in the No-fever group (both, p < 0.05). The total PCEA duration and total PCEA amount were positively correlated with the incidence of fever (both, p < 0.05). The diagnostic cutoff value for fever was 383 min, with a sensitivity of 78.6% and specificity of 57.3%. The mean temperature-time curves showed that parturients who developed fever had a steeper rise in temperature. CONCLUSIONS: This study showed that there were weak time- and dose-dependent correlations between PCEA and maternal fever during delivery. A total PCEA duration exceeding 6.3 h was associated with an increase in the duration of maternal intrapartum fever.

Cooling treatment on the reduction of category II fetal tracings.

OBJECTIVES: Epidural-related maternal fever increases the incidence of Category II fetal tracings. To compare the effectiveness of low-flow oxygen inhalation and cooling treatment for parturients with Category II fetal tracings caused by epidural-related maternal fever. METHODS: We investigated 200 pregnant women who accepted epidural analgesia during labor and had body temperature exceeding 38 °C during labor. Among the patients, 99 and 101 were randomly allocated to receive cooling treatment group (control group) and oxygen inhalation (oxygen group), respectively. The primary outcome was the incidence of Category II fetal heart rate tracings. RESULTS: The incidence of Category II fetal heart rate tracings in the control group was significantly higher than that in the oxygen group. However, no significant differences were noted between the two groups in terms of the Apgar scores; amniotic fluid turbidity; or maternal outcomes, including cesarean section rate, forceps delivery rate, lateral resection rate, manual removal of placenta rate, the amount of intrapartum hemorrhage, and hemorrhage at postpartum 2 h. Oxygen inhalation therapy was more effective than cooling treatment in reducing the incidence of Category II tracings. CONCLUSION: Low-flow and short-term oxygen inhalation for parturients with epidural-related maternal fever reduces the incidence of Category II fetal heart rate tracings, but had no significant influence on the mode of delivery or neonatal outcomes.

A Gate-Tunable Ambipolar Quantum Phase Transition in a Topological Excitonic Insulator.

Coulomb interactions among electrons and holes in 2D semimetals with overlapping valence and conduction bands can give rise to a correlated insulating ground state via exciton formation and condensation. One candidate material in which such excitonic state uniquely combines with non-trivial band topology are atomic monolayers of tungsten ditelluride (WTe2 ), in which a 2D topological excitonic insulator (2D TEI) forms. However, the detailed mechanism of the 2D bulk gap formation in WTe2 , in particular with regard to the role of Coulomb interactions, has remained a subject of ongoing debate. Here, it shows that WTe2 is susceptible to a gate-tunable quantum phase transition, evident from an abrupt collapse of its 2D bulk energy gap upon ambipolar field-effect doping. Such gate tunability of a 2D TEI, into either n- and p-type semimetals, promises novel handles of control over non-trivial 2D superconductivity with excitonic pairing.

Association between epidural-related maternal fever and short-and long-term prognosis of parturients: A prospective observational study.

We aimed to explore the association between epidural-related maternal fever (ERMF) and prognosis of parturients. 159 parturients who underwent vaginal delivery under labor epidural analgesia (LEA) received noninvasive continuous core body temperature monitoring. 122 of them completed the 42-day postpartum follow-up. Parturients with body temperature ≥38°C during labor were categorized as the Fever group, while the others were categorized as the No-Fever group. Compared to No-Fever group, Fever group had a greater proportion of primiparas, greater gestational age of parturients, and longer third stage of labor. The cesarean section and forceps delivery rates, and the amount of intrapartum hemorrhage in Fever group were significantly higher. There were no significant between-group differences with respect to puerperal infection, and amniotic fluid turbidity degree, neither significant between-group difference at 42-days postpartum. We found that ERMF was associated with some short-term outcomes. However, it showed no relation with long-term prognosis of the parturients at 42-days postpartum.

Tuning the many-body interactions in a helical Luttinger liquid.

In one-dimensional (1D) systems, electronic interactions lead to a breakdown of Fermi liquid theory and the formation of a Tomonaga-Luttinger Liquid (TLL). The strength of its many-body correlations can be quantified by a single dimensionless parameter, the Luttinger parameter K, characterising the competition between the electrons' kinetic and electrostatic energies. Recently, signatures of a TLL have been reported for the topological edge states of quantum spin Hall (QSH) insulators, strictly 1D electronic structures with linear (Dirac) dispersion and spin-momentum locking. Here we show that the many-body interactions in such helical Luttinger Liquid can be effectively controlled by the edge state's dielectric environment. This is reflected in a tunability of the Luttinger parameter K, distinct on different edges of the crystal, and extracted to high accuracy from the statistics of tunnelling spectra at tens of tunnelling points. The interplay of topology and many-body correlations in 1D helical systems has been suggested as a potential avenue towards realising non-Abelian parafermions.

The Influence of Different Dexmedetomidine Doses on Cognitive Function at Early Period of Patients Undergoing Laparoscopic Extensive Total Hysterectomy.

Background: This study aims to analyze the influence of different dexmedetomidine doses on cognitive function. It works on early periods of patients undergoing laparoscopic extensive total hysterectomy. Method: 119 patients with gynecological cancer underwent a laparoscopic extensive total hysterectomy. The operation was performed at the Affiliated Women's and Children's Hospital of Xiamen University from January 2019 to June 2020. The score of MoCA and the level of TNF-α, IL-6, S-100ß protein, NSE, and GFAP of each group were compared 1 day before and after operation and 3 and 7 days after operation. Result: In four groups, remifentanil, sufentanil, and propofol were given in the following order: group A > group D > group C > group B. Group A > group D > group C in terms of time spent in the recovery room, extubation, and recovery from anesthesia. The difference between groups B and C was not significant (P > 0.05). Compared with group A, group B scored higher in MoCA at 1 day (T1), 3 days (T2), and 7 days (T3) after operation (P < 0.05). At the same scoring point, the score was group B > group C > group D > group A. The POCD of four groups all occurred at 3 days after surgery. Compared with the T0 point, the level of TNF-α and IL-6 of the four groups at T1 and T2 was significantly increased (P < 0.05). At T3, the level of TNF-α and IL-6 gradually decreased. At various periods, the levels of S-100 protein, NSE, and GFAP in groups B, C, and D were lower than those in group A (P0.05). Group B had a substantially higher rate of bradycardia than the other three groups (P0.05). The incidence of chills, respiratory depression, and restlessness in group A differed significantly from the other three groups (P < 0.05). Conclusion: Using 0.5 µg/kg dexmedetomidine during the perianaesthesia can effectively reduce anesthetic drugs in patients. They had a laparoscopic extensive complete hysterectomy, which helps to reduce the adverse responses and the occurrence of POCD while also protecting brain function.

Year-round film mulching system with monitored fertilization management improve grain yield and water and nitrogen use efficiencies of winter wheat in the dryland of the Loess Plateau, China.

Year-round film mulching in winter wheat field facilitates rainwater storage in summer fallow period and reduces water evaporation in growing reason, and then increases water use efficiency in the dryland of the Loess Plateau, China. Optimized fertilization further promotes fertilizer utilization efficiencies. In this study, plastic film mulching was extended from plant growth season to summer fallow, and fertilizers were applied by monitoring soil nutrient availability. Field trials were conducted in the dryland of the Loess Plateau over 4 years by using four types of cultivation to investigate the effects of year-round plastic film mulching with monitored fertilization on utilization efficiencies of rainwater and nitrogen (N), and winter wheat yield. The four types of cultivation were farmer practice (FP), ridge-furrow with plastic film mulching system plus conventional fertilization(RPCF), ridge-furrow with plastic film mulching system plus monitored fertilization (RPFM), and flat soil surface with plastic film mulching system plus monitored fertilization (FPFM). Our results indicate that the average yield of winter wheat in RPFM and FPFM treatments was 4491 kg ha-1. Compared with FP treatment, the combined effects of monitored fertilization and film mulching(RPFM and FPFM treatments) could increase grain yield in the range of 24.7 to 42.1%. The film mulching extended to the fallow season increased the water storage in 2 m depth of soil profile, and the amount of soil water storage in the summer fallow period increased by 27 to 30% in FPFM treatment than FP treatment. After 4-year consecutive planting of wheat, the accumulation of nitrate-N in 2 m soil reached 277 kg·ha-1 in the FP treatment, which is 87.7% higher than of the level at the beginning of the experiment. Seventy-five percent of nitrate-N was distributed in the soil layer of 0-120 cm. In addition, the residual nitrate-N showed downward leaching with rainfall during the experiment. The RPFM and FPFM treatments reduced the apparent loss and residual levels of soil N, whereas increased its apparent mineralization compared with FP treatment. The FPFM treatment exhibited a greater utilization of residual nitrate-N from previous years and showed a higher amount of the mineralized N from soil organic matter, therefore leading to a relatively high apparent utilization rate of N (56.7%). Considering both grain yield production and utilization efficiencies of water and N, FPFM with year-round mulching was the most effective cultivation measure for winter wheat in the Loess Plateau.

Risk assessment of water pollution sources based on an integrated k-means clustering and set pair analysis method in the region of Shiyan, China.

Source water areas are facing many potential water pollution risks. Risk assessment is an effective method to evaluate such risks. In this paper an integrated model based on k-means clustering analysis and set pair analysis was established aiming at evaluating the risks associated with water pollution in source water areas, in which the weights of indicators were determined through the entropy weight method. Then the proposed model was applied to assess water pollution risks in the region of Shiyan in which China's key source water area Danjiangkou Reservoir for the water source of the middle route of South-to-North Water Diversion Project is located. The results showed that eleven sources with relative high risk value were identified. At the regional scale, Shiyan City and Danjiangkou City would have a high risk value in term of the industrial discharge. Comparatively, Danjiangkou City and Yunxian County would have a high risk value in terms of agricultural pollution. Overall, the risk values of north regions close to the main stream and reservoir of the region of Shiyan were higher than that in the south. The results of risk level indicated that five sources were in lower risk level (i.e., level II), two in moderate risk level (i.e., level III), one in higher risk level (i.e., level IV) and three in highest risk level (i.e., level V). Also risks of industrial discharge are higher than that of the agricultural sector. It is thus essential to manage the pillar industry of the region of Shiyan and certain agricultural companies in the vicinity of the reservoir to reduce water pollution risks of source water areas.

[N2O emission from an intensively managed greenhouse vegetable field in Nanjing suburb, Jiangsu Province of East China].

By using static opaque chamber and gas chromatography, this paper studied the dynamic changes of N2O fluxes and their relationships with soil temperature, soil moisture content, and soil nitrate and ammonium contents in an intensively managed greenhouse celery-Tung choy-Bok choy-amaranth rotation field and in a bare fallow land in Nanjing suburb. The cumulative N2O emission from the rotation vegetable field was as high as 137.2 kg N x hm(-2), being significantly higher than that from the bare fallow land (29.2 kg N x hm(-2)), and the N2O-N emission factor of the rotation vegetable field ecosystem was up to 4.6%. In the rotation field, the planting of Tung choy had the greatest contribution to the annual cumulative N2O emission, occupying 53.5% of the total, followed by the planting of Bok choy (31.9%), celery field (4.5%), and amaranth (4.8%). The N2O flux of the rotation field had significant positive correlation with soil temperature, the Q10 being 2.80, but no significant correlations with soil moisture content and soil nitrate and ammonium contents.