A site-resolved two-dimensional quantum simulator with hundreds of trapped ions.

A large qubit capacity and an individual readout capability are two crucial requirements for large-scale quantum computing and simulation1. As one of the leading physical platforms for quantum information processing, the ion trap has achieved a quantum simulation of tens of ions with site-resolved readout in a one-dimensional Paul trap2-4 and of hundreds of ions with global observables in a two-dimensional (2D) Penning trap5,6. However, integrating these two features into a single system is still very challenging. Here we report the stable trapping of 512 ions in a 2D Wigner crystal and the sideband cooling of their transverse motion. We demonstrate the quantum simulation of long-range quantum Ising models with tunable coupling strengths and patterns, with or without frustration, using 300 ions. Enabled by the site resolution in the single-shot measurement, we observe rich spatial correlation patterns in the quasi-adiabatically prepared ground states, which allows us to verify quantum simulation results by comparing the measured two-spin correlations with the calculated collective phonon modes and with classical simulated annealing. We further probe the quench dynamics of the Ising model in a transverse field to demonstrate quantum sampling tasks. Our work paves the way for simulating classically intractable quantum dynamics and for running noisy intermediate-scale quantum algorithms7,8 using 2D ion trap quantum simulators.

[Relationship between vertebral CT values and bone mineral density in patients with chronic obstructive pulmonary disease].

Objective: To explore a simple method for early detection of osteoporosis in patients with chronic obstructive pulmonary disease (COPD), by analyzing the correlation between computed tomography (CT) values of the thoracolumbar vertebrae and dual energy X ray absorptiometry (DXA). Methods: 86 patients with acute exacerbation of COPD were included in this study. The average age of the patients, including 57 males and 29 females, was 74±10 years. They all received chest CT and DXA examination within 1 month after admission. The relation between each CT value from 6(th) thoracic vertebrae (T6) to 1(st) lumbar (L1) and T-score measured by DXA was analyzed by linear correlation analysis with SPSS 17.0 software. Results: The mean CT value of T6-L1 was significantly lower in patients with osteoporosis than that in patients with normal bone mineral density (P<0.05). The CT values of T6-L1 were positively correlated with T-score (P<0.001). The ROC curve analysis of T6-L1 CT value showed that the area under ROC curve of L1 CT value was the largest, and therefore the accuracy of diagnosis of osteoporosis by L1 CT value was better.A L1 CT value lower than 100 HU was proposed as the threshold for lower bone mass or osteoporosis in the patients. Conclusion: It is possible to detect osteoporosis in patients with COPD through evaluating the CT values of T6-L1. This method could potentially reduce X-ray irradiation and expense. Early detection and intervention in patients with COPD and osteoporosis could improve the prognosis of patients.

The protective effect and its mechanism of 3-n-butylphthalide pretreatment on cerebral ischemia reperfusion injury in rats.

OBJECTIVE: To investigate the potential effect of 3-n-butylphthalide (NBP) pretreatment on the cerebral ischemia/reperfusion injury in rats and the relevant mechanism. MATERIALS AND METHODS: A total of 90 rats was divided into three groups: Sham operation group (Sham group), ischemia-reperfusion group (I-R group), and NBP pretreatment group (NBP group 75 mg·kg-1·d-1 gavage). Pre-treatment was given once a day within 1 week before establishing the rat model of cerebral ischemia-reperfusion injury. The middle cerebral artery occlusion (MACO) rat models were established with the improved Longa-Zea method on the 7th day after ischemia for 2 h and reperfusion for 24 h in all the rats. We detected the cerebral infarction, the pathologic change of brain, the apoptosis of nerve cell, the production levels of reactive oxygen species (ROS), the content of malonaldehyde (MDA) and the activity of superoxide dismutase (SOD), the water content and the permeability of blood-brain barriers (BBB). In addition, we also observed the expressions of mitogen-activated protein kinase (MAPK, p-38, JNK, ERK1/2) and cleaved caspase-3 in the hippocampus tissues. RESULTS: Compared with Sham group, we discovered that NBP significantly reduced infarction area, cell apoptosis, BBB damage and water content. Further, we found that NBP could also decrease ROS and MDA, and increase SOD activity in brain tissues of rats with a cerebral ischemia-reperfusion injury. Moreover, results showed that NBP also inhibited the levels p38 and JNK. CONCLUSIONS: NBP protected the cerebral from I/R injury, providing ideas for the expansion of clinical adaptability of NBP and possible approaches for its application.

How Chinese clinicians contribute to the improvement of maternity care.

Clinicians in China are deeply involved in efforts to improve maternity care throughout the country. A Women's Health section has been established in the Chinese Society of Obstetrics and Gynecology. Staff of tertiary hospitals participate in perinatal surveillance of cities, including regular maternal and perinatal mortality meetings and comparative inter-hospital evaluations of service and clinical statistics. Clinicians from larger urban centers visit rural hospitals to provide guidance in management of high risk patients.

PIP: China is a developing country with 1/5 of the world's population. Recently, systematic maternal health care has come to many cities. Lately, too, with the introduction of perinatal surveillance, maternity care has entered a period of integrated perinatal health care. In cities, maternal mortality has dropped to 20/1000,000. In rural areas, it can be 10 times that. The distribution of qualified personnel is uneven. Hospital clinicians are involved in the Chinese Society of Obstetrics and Gynecology. They attend the Society's National Congress. In Beijing, maternal health service is regionalized. Senior staff responsibilities include consultation and teaching rounds, committee meetings, and quality evaluation. Rural China lags behind the rest of the nation in health care. In 1990, risk approach strategy was begun. A pilot study was conducted at Beijing Medical University, 4 army hospitals, and Beijing Women's Health Institute. Physicians from Beijing worked at the pilot site, Shunyi county once every 2 weeks. 7 of 29 townships were randomly selected to cover a population of 100,000, The Maternal-Child Health (MCH) structure was used. This is 3-tiered--village, township, and county. During the 1st year, MCH workers sought pregnant mothers and brought them to the township center for antenatal care early in their pregnancies. These women had 2212 babies; the perinatal mortality rate was 26.7/1000. The causes of death were identified. Risk scoring was attempted during the 2nd year. Most of those women at risk were attended in the county hospital. However, 60% of the perinatal deaths occurred there. A neonatal ward was established in the county hospital. Workers were taught such skills as rotation of labor presentations, and monitoring of hypertensive diseases of pregnancy. Neonatal mortality then dropped from 14/1000 to 8/1000; death from low birth weight decreased sharply. In 1986, there were 2335 births; the perinatal mortality was 17.6/1000. Risk approach is feasible and effective in lowering perinatal mortality and morbidity in rural Beijing. The county MCH Institute is teaching workers in 29 townships to practice risk approach.

Physical and sexual abuse of women before, during, and after pregnancy.

OBJECTIVES: To examine patterns of physical and sexual abuse before, during, and after pregnancy. METHODS: A community-based interview survey of a representative group of women with children aged 6-18 months was carried out between November 1, 2001, and February 28, 2002, in 32 communities of the Tianjing, Liaoning, Henan, and Shannxi provinces. RESULTS: The overall prevalence of physical and sexual abuse (occurring before, during, and after pregnancy) was 11.7%. The prevalence of physical and sexual abuse before pregnancy was 8.5%, compared with 3.6% during pregnancy and 7.4% during an average postpartum period of 11 months. Abuse before pregnancy was a strong indicator of abuse during pregnancy and after delivery, and abuse during a previous period was a strong indicator of subsequent abuse. Most abuse was recurrent and not severe. CONCLUSIONS: Routine screening for abuse in the maternity services setting is advocated to decrease the effect of abuse on women and their children.

A case of renal γ2 heavy-chain deposition disease accompanied by rapid progressive renal failure.

BACKGROUND: The recently described heavy-chain deposition disease (HCDD) is a comparatively rare monoclonal immunoglobulin disorder characterized histopathologically by glomerular and tubular basement membrane deposition of nonamyloidotic monoclonal heavy chains without associated light chains. METHOD: We have described a case of γ2-HCDD presenting with proteinuria, microhematuria, severe hypertension, and rapidly progressive renal failure, which serum creatinine level was only 1.52 mg/dL in early stage HCDD, and the clinicopathologic features of this case have been compared with other reported cases of γ2-HCDD. RESULTS: Renal biopsy disclosed nodular sclerosing glomerulopathy. Immunofluorescence analysis revealed IgG2 (2+) heavy chain and C3 (+) in the mesangium and along the capillary walls and tubular basement membranes without IgA, IgM, κ and λ light chains. Electron microscopy revealed electron-dense deposits along the glomerular and tubular basement membranes as well as in the mesangium. Moreover, regardless of therapy, the condition of the patient progressively deteriorated, with less than 3 months of renal survival. CONCLUSION: Rapid progressive renal failure was a common feature in both cases of γ2-HCDD. We propose that a possible link exists between prognosis of renal HCDD and the subclass of heavy chain deposited in the kidney.

Maternal mortality in China.

Within 10 years of the establishment of the People's Republic, maternal mortality in China had fallen by 98%. High values, however, persist in the less developed parts of the country.

PIP: 2 studies have been done in China: 1) a longitudinal study on maternal mortality in Beijing from 1949 to 1983; and 2) a cross-sectional study on maternal mortality in the year 1984 in 21 of 29 provinces, municipalities, and autonomous regions. A maternal and child health network for care and referral of abnormal cases was set up with ambulances and transfusion facilities in place and training for traditional birth attendants. Aseptic delivery reduced the number of deaths due to sepsis from 213/100,000 live births to 4.2 in 5 years and to 0 in 9 years. Deaths from hemorrhage (including ruptured uterus) dropped by 86% in 5 years. With legalized abortion came a dramatic fall in maternal mortality from 685,100/000 live births to 15, a decrease of 98%. In 1949, 27% of women who died in childbirth had received hospital care; another 27% had no cure. In 1958, however, 80% of the fetal cases had obtained hospital care; the remaining 20% had been seen by a traditional practitioner or health worker. From 1959-68, the total maternal mortality was 1.3-28.1/1 00,000. From 69-78, the turmoil of the cultural revolution had "ill effects" on maternal and child health but by 1979, order was brought back again. The cross-sectional study covered a population of about 177 million. About 2.5 million live births occurred. 1211 maternal deaths were registered for a maternal mortality rate of 48.4/100,000. Maternal mortality varied a good deal in different parts of the country--from 17.7 in Shanghai to 108.2 in the region of the Hai people in Ningxia in northwest China. Maternal mortality rates correspond roughly to the level of economic development. The 5 main causes of death were hemorrhage, heart failure, pregnancy- induced hypertension (including eclampsia), postpartum infection and liver failure.