Chemically aware unitary coupled cluster with ab initio calculations on an ion trap quantum computer: A refrigerant chemicals' application.

Circuit depth reduction is of critical importance for quantum chemistry simulations on current and near term quantum computers. This issue is tackled by introducing a chemically aware strategy for the unitary coupled cluster ansatz. The objective is to use the chemical description of a system to aid in the synthesis of a quantum circuit. We combine this approach with two flavors of symmetry verification for the reduction of experimental noise. These methods enable the use of Quantinuum's System Model H1 ion trap quantum computer for a 6-qubit quantum subspace expansion calculation. We present (i) calculations to obtain methane's optical spectra; (ii) an atmospheric gas reaction simulation involving [CH3⋅-H-OH]‡. Using our chemically aware unitary coupled cluster state-preparation strategy in tandem with state of the art symmetry verification methods, we improve device yield for CH4 at 6 qubits. This is demonstrated by a 90% improvement in two-qubit gate count and a reduction in relative error to 0.2% for electronic energy calculated on System Model H1.

A mass-selective ion transfer line coupled with a uniform supersonic flow for studying ion-molecule reactions at low temperatures.

A new approach based on the uniform supersonic flow technique-a cold, thermalized de Laval expansion offering the advantage of performing experiments with condensable species-has been developed to study ion-molecule reactions at low temperatures. It employs a mass-selective radio frequency transfer line to capture and select ions from an adaptable ionization source and to inject the selected ions in the core of the supersonic expansion where rate coefficients and product branching can be measured from room temperature down to ∼15 K. The transfer line incorporates segmented ion guides combining quadrupolar and octapolar field orders to maximize transmission through the differential apertures and the large pressure gradients encountered between the ionization source (∼mbar), the quadrupole mass filter (∼10-5 mbar), and the de Laval expansion (∼mbar). All components were designed to enable the injection of cations and anions of virtually any m/z ratio up to 200 at near ground potential, allowing for a precise control over the momentum and thermalization of the ions in the flow. The kinetics and branching ratios of a selection of reactions have been examined to validate the approach. The technique will be instrumental in providing new insight on the reactivity of polyatomic ions and molecular cluster ions in astrophysical and planetary environments.

Enhanced surface ozone during the heat wave of 2013 in Yangtze River Delta region, China.

Under the background of global warming, occurrence of heat waves has increased in most part of Europe, Asia and Australia along with enhanced ozone level. In this paper, observational air temperature and surface ozone in the Yangtze River Delta (YRD) region of China during summer of 2013, and the regional chemistry-climate model (RegCM-CHEM4) were applied to explore the relationship between heat wave and elevated ground-level ozone. Observations indicated that YRD experienced severe heat waves with maximum temperature up to 41.1°C, 6.1°C higher than the definition of heat wave in China, and can last for as long as 27days. Maximum ozone reached 160.5ppb, exceeding the national air quality standard (secondary level) as 74.7ppb. Moreover, ozone was found to increase at a rate of 4-5ppbK-1 within the temperature range of 28-38°C, but decrease by a rate of -1.3~-1.7ppbK-1 under extremely high temperature. A typical heat wave case (HW: 24/7-31/7) and non-heat wave case (NHW: 5/6-12/6) were selected to investigate the mechanism between heavy ozone and heat waves. It was found that chemical reactions play the most important role in ozone formation during HW days, which result in 12ppb ozone enhancement compared to NHW days. Chemical formation of ozone can be influenced by several factors. During heat waves, a more stagnant condition, controlled by anti-cyclone with sink airflow, led to less water vapor in YRD from south and contributed to less cloud cover, which favored a strong solar radiation environment and ozone significantly increasing. High temperature also slightly promote the effect of vertical turbulence and horizontal advection, which beneficial to ozone remove, but the magnitude is much smaller than chemical effect. Our study suggests that the chemical reaction will potentially lead to substantial elevated ozone in a warmer climate, which should be taken into account in future ozone related issues.

Study of heat-stress levels in naturally ventilated sheep barns during heat waves: development and assessment of regression models.

It is well documented that heat-stress burdens sheep welfare and productivity. Peak heat-stress levels are observed when high temperatures prevail, i.e. during heat waves; however, continuous measurements inside livestock buildings are not usually available for long periods so as to study the variation of summer heat-stress levels for several years, especially during extreme hot weather. Α methodology to develop a long time series of summer temperature and relative humidity inside naturally ventilated sheep barns is proposed. The accuracy and the transferability of the developed linear regression models were verified. Temperature Humidity Index (THI) was used to assess sheep's potential heat-stress. Τhe variation of THI inside a barn during heat wave and non-heat wave days was examined, and the results were comparatively assessed. The analysis showed that sheep were exposed to moderate, severe, and extreme severe heat-stress in 10, 21 and 66 % of hours, respectively, during heat wave days, while the corresponding values during non-heat wave days were 14, 33 and 43 %, respectively. The heat load on sheep was much higher during heat wave events than during non-heat wave periods. Additionally, based on the averaged diurnal variation of THI, it was concluded that extreme severe heat-stress conditions were prevailing between 1000 and 2400 hours local time during heat wave days. Cool off night periods were never and extremely rarely detected during heat wave and non-heat wave days, respectively.

Evaluation of thermal perception in schoolyards under Mediterranean climate conditions.

The aim of this paper was to study qualitatively and quantitatively the thermal perception and corresponding heat stress conditions that prevail in two schoolyards in a coastal city in central Greece. For this purpose, meteorological parameters (i.e., wind speed, temperature, relative humidity, solar radiation) were recorded at 70 and 55 measuring points in the schoolyards, from 14:00 to 15:30 local time, during May and June of 2011. The measuring points were distributed so as to get measurements at points (a) directly exposed to the sun, (b) under the shadow of trees and building structures, and (c) near building structures. Cluster analysis was applied to group observations and revealed places that are microclimatically homogeneous. Thermal perception and heat stress conditions were assessed by means of the physiologically equivalent temperature (PET, °C), and the results are presented in relevant charts. The impact of material's albedo, radiation's reflection by structures and obstacles, and different tree species on thermal perception and heat stress conditions was also assessed. The analysis showed that trees triggered a reduction of incident solar radiation that ranged between 79 and 94 % depending on tree's species, crown dimension, tree height, and leaf area. PET values were mainly affected by solar radiation and wind speed. Trees caused a reduction of up to 37 % in PET values, while a 1-m s(-1) increase in wind speed triggered a reduction of 3.7-5.0 °C in PET value. The effective shading area in the two schoolyards was small, being 27.5 and 11 %. The results of this study could be exploited by urban planning managers when designing or improving the outdoor environment of a school complex.

Double-blind ureteral duplication: a rare urologic anomaly.

We present an extremely infrequent urologic entity of asymptomatic double-blind ureteral duplication in an 8-year-old girl. Contemporary imaging modalities provided major assistance in the diagnosis. Surgical management is advocated because of the potential for future complications, such as lithiasis, obstruction of the collecting system, and renal failure.

Community-associated Staphylococcus aureus infections and nasal carriage among children: molecular microbial data and clinical characteristics.

An increasing number of infections caused by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) carrying the Panton-Valentine leukocidin (PVL) genes was recently identified in Greece. In the present study, 170 patients with S. aureus infections and 123 uninfected children (<15 years old) who had been tested for nasal carriage were evaluated during a 2-year period. The MecA, PVL and superantigen family genes, and MRSA clones, were investigated by molecular methods. Sites of infection and laboratory findings for patients were recorded. The results were compared and statistically analysed. Among 123 uninfected children 73 (59%) carried S. aureus, including four MRSA strains. Of these, three MRSA and three methicillin-sensitive S. aureus (MSSA) strains were PVL-positive (p <0.0001). Ninety-six patients (96/170) exhibited skin and soft-tissue infections (SSTIs), and 74 exhibited invasive infections. The incidence of staphylococcal infections increased during July to September each year. In total, 110 S. aureus isolates were PVL-positive (81 from SSTIs and 29 from invasive infections, p <0.0001). Ninety-nine out of 106 MRSA (93%) isolates from 170 patients carried the PVL genes (p <0.0001); 97 belonged to the clonal complex CC80. Leukocyte and polymorphonuclear cell counts were higher among children with MRSA infections (p <0.005). MSSA predominated among patients with invasive infections (43/74), and carried mainly genes of the superantigen family. Children <5 years of age showed a higher risk of MRSA infection. The present study demonstrates that infections due to PVL-positive CA-MRSA spread easily among children, and SSTIs can lead to invasive infections. Nasal colonization may be an additional factor contributing to the emergence of CA-MRSA.

Ion thermalization using pressure transients in a quadrupole ion trap coupled to a vacuum matrix-assisted laser desorption ionization source and a reflectron time-of-flight mass analyzer.

Efficient trapping and detection of intact peptide ions is demonstrated in a quadrupole ion trap (QIT) coupled to an external vacuum matrix-assisted laser desorption ionization (MALDI) source. Deactivation of metastable ions generated by MALDI is achieved in a pressure transient environment inside the QIT established by pulsing gas to access the higher pressures required for fast thermalization, without affecting vacuum conditions in the ion source and time-of-flight (TOF) mass analyzer. Pressure transients are experimentally determined and a threshold of approximately 10 mTorr is identified where internally excited ions, which commonly observed to dissociate upon injection in a QIT, are stabilized. Fragment-free spectra are presented for a set of peptides by using 2,5-dihydroxybenzoic acid (DHB) as a matrix, and significantly reduced fragmentation is observed by using a-cyano-4-hydroxycinnamic acid (CHCA). Intact peptide spectra of a protein tryptic digest are also recorded with CHCA. The process of translational cooling for externally injected ions in a dynamic pressure environment is visualized by using ion trajectory simulations that employ hard sphere collisions. Statistical theory of dynamic equilibrium of ions stored in rf fields is applied to our QIT to characterize a translationally thermalized ion cloud, to explain observed ejection efficiency into the TOF mass analyzer, and to further discuss collisional deactivation of metastable ions.

Differential mobility separation of ions using a rectangular asymmetric waveform.

The performance of a planar differential mobility spectrometer (DMS) is investigated when operated in air at ambient pressure and driven by a rectangular asymmetric waveform, limited to frequencies of <1.2 MHz and voltage pulse amplitudes of <1 kV with steep rise times of the order of approximately 15 ns. Independent control of frequency, voltage pulse amplitude, and duty cycle allow for characterizing the DMS in terms of transmission, resolution and separation. The tradeoff between sensitivity and resolution and the effect of duty cycle on instrument performance are demonstrated experimentally. The dependence of ion mobility on the magnitude of the electric field determines the displacement of ions measured by the DC compensation voltage as a function of the duty cycle. Optimum values for the duty cycle exist for the separation of A- and C-type ions, while, B-type ions exhibit a more complex behavior. An analytical expression for describing the effect of duty cycle on the separation of the ions, determined by variations in the compensation voltage, is developed and compared to experimental results obtained in air below 75 Td using estimated alpha parameters for a set of ketones. In this context, errors associated with the calculation of alpha parameters using polynomials of even powers are highlighted.

[Sacroilitis and osteomyelitis of the humeral bone du to Brucella melitensis in an adolescent]. / Sacro-iléite et ostéo-myélite de l'humérus dues à Brucella melitensis chez une adolescente.

We describe a case of a 10 year old patient who presented with intermittent fever and pain in the pelvis and elbow region. From the history, imaging and laboratory tests, a diagnosis of Brucella sacroiliitis and elbow osteoarthritis was made. The patient was given an antibiotic treatment for 3 months with a progressive improvement of symptoms to complete recovery, and normalization of imaging and laboratory findings.

Methicillin-resistant Staphylococcus aureus producing Panton-Valentine leukocidin as a cause of acute osteomyelitis in children.

Staphylococcus aureus was identified as the cause of acute childhood osteomyelitis in 19 patients. A single clone of community-acquired methicillin-resistant S. aureus (MRSA) carrying the type IV mecA staphylococcal cassette chromosome and the Panton-Valentine leukocidin (PVL) genes was isolated from five patients. Among the remaining 14 patients, two methicillin-sensitive S. aureus (MSSA) isolates were PVL-positive. The maximal erythrocyte sedimentation rate and C-reactive protein values, and the time required for normalisation, were significantly different in patients with PVL-positive strains (MRSA and MSSA), suggesting that the production of PVL is an important factor that contributes to the course of the disease.

Co-existence of Chiari malformation type I and Epstein-Barr virus meningoencephalitis in a 3-year-old child: case report and review of the literature.

In the present report we describe an unusual case of a 3-year-old girl who was admitted to our hospital with Epstein-Barr virus meningoencephalitis. Brain magnetic resonance imaging revealed diffuse abnormalities in white matter and Chiari I malformation with cervical and thoracic hydro-syringomyelia.

Epidemiology of seropositive myasthenia gravis in Greece.

OBJECTIVES: To study the epidemiological characteristics of myasthenia gravis in Greece. METHODS: A population based study was carried out of seropositive myasthenia gravis in Greece for the period from 1 January 1983 to 30 June 1997; 843 patients were studied. RESULTS: The average annual incidence for the period 1992-7, for which the database is complete, was 7.40/million population/year (women 7.14; men 7.66). On 1 July 1997, there were 740 prevalent cases. The point prevalence rate was 70.63/million (women 81.58; men 59.39). The average overall annual mortality rate in the patients was 0.67/million population (women 0.53; men 0.82), and the mortality rate attributed to myasthenia gravis was 0.43/million population (women 0.41; men 0.45). The average age at onset was 46.50 years (women 40.16; men 54.46), and the mean age of the prevalent patients was 52.58 (women 47.65; men 59.48). The women:men incidence ratio was 1:1.04, and the prevalence ratio was 1.41:1. It is predicted that the prevalence and women: men prevalence ratio would increase if the patient list included all patients with a date of onset before 1983. CONCLUSIONS: The largest epidemiological study ever performed on myasthenia gravis is presented. The most important epidemiological indexes are provided.

Correlative analysis of the sagittal profile of the spine in patients with beta-thalassemia and in healthy persons.

This prospective study compares several roentgenographic parameters of the thoracic and lumbar spine in patients with beta-thalassemia and in healthy persons who served as controls. Eighty-four patients with beta-thalassemia and 84 age- and gender-matched healthy persons were examined clinically and radiologically (thoracic kyphosis, lumbar lordosis, and vertebral and sacral inclination). Although there was a significant difference in the vertebral inclination from T6 to L1, L4, and L5 between patients and controls, thoracic kyphosis and lumbar lordosis did not differ in the two groups. The apical vertebra of the thoracic kyphosis in patients and controls was T7 and T6, respectively, whereas L4 was the apical vertebra of the lumbar lordosis in both groups. There were no age- or gender-related differences in the magnitude of sacral inclination, thoracic kyphosis, or lumbar lordosis in the patients with beta-thalassemia compared with controls. Lumbar lordosis was significantly correlated with sacral inclination in both patients with beta-thalassemia and controls. Beta-thalassemia does not affect sagittal profile of the thoracic and lumbar spine but it is associated by structural changes on the frontal plane of the spine that are expressed as a high prevalence of scoliosis.

Prevention of passively transferred experimental autoimmune myasthenia gravis by Fab fragments of monoclonal antibodies directed against the main immunogenic region of the acetylcholine receptor.

The muscle acetylcholine receptor loss, responsible for the clinical symptoms of myasthenia gravis, is due mainly to mechanisms dependent on the bivalent character of the anti-receptor antibodies. In cell culture, univalent Fab fragments of monoclonal antibodies (mAbs) directed against the main immunogenic region (MIR) of the acetylcholine receptor are able to protect the receptor against the action of the intact antibodies. To investigate the potential therapeutic use of this approach, we examined the ability of the Fab fragment of anti-MIR mAb195 (Fab195) to protect the receptor in vivo against two anti-MIR mAbs. Because of the rapid clearance of Fab fragments from the circulation, Lewis rats were treated repeatedly with Fab195. The Fab fragment significantly protected muscle receptors against antibody-mediated loss and was very efficient in providing protection against clinical symptoms when its administration was commenced before, simultaneously with, or 2 h after, mAb injection. Twenty-four hours after mAb injection, the protected rats only showed mild myasthenic symptoms, whereas those which only received intact antibodies were moribund or dead. These results suggest that, once modified to ensure their low immunogenicity and a long half-life, anti-MIR Fab fragments might be useful in the specific immunotherapy of myasthenia gravis.

Concentration of iron and distribution of iron and transferrin after experimental iron overload in rat tissues in vivo: study of the liver, the spleen, the central nervous system and other organs.

The purpose of this study was to estimate the iron concentration in the liver, spleen and brain of control rats and rats overloaded with iron and to determine the distribution of iron and of transferrin (TF). Iron was administered to Wistar rats by food supplemented with 3% carbonyl iron for 3 months, or intraperitoneally, or intraveneously as iron polymaltose for 4 months (total administered dose: 300 or 350 mg/rat, respectively). Iron concentration was estimated by atomic absorption spectrophotometry and iron- and TF-distribution histochemically and immunohistochemically, respectively. In control rats the organ with the highest iron content was the spleen, followed by the liver and brain. After iron loading the increase of iron in the liver was greater than that of the spleen; iron concentration in the brain did not change significantly. Distribution of iron in the liver was in Kupffer cells throughout the lobule and in hepatocytes at its periphery. No difference in the number of positive cells or staining intensity for TF was observed between control rats and iron overloaded animals in the liver or central nervous system (CNS); the spleen was negative for TF. Distribution of TF in the liver showed a centrilobular localisation in hepatocytes. TF reaction in the brain occurred in oligodendrocytes, vessel walls, choroid plexus epithelial cells and some neurons. In conclusion, experimental iron overload in rats leads to iron uptake mainly by reticuloendothelial (RE) cells and hepatocytes, indicating that hepatocytes are of particular importance for iron metabolism. Iron uptake by the brain was not significant, probably because the brain is protected against iron overload. Iron overload did not influence location and quantity of TF in the liver and CNS, whereas the visualisation of iron and TF did not coincide. This indicates that TF may have other functions beyond iron transport.

Response to interferon alfa-2b therapy in mutitransfused children with beta-thalassemia and chronic hepatitis C.

Hepatitis C virus is responsible for the majority of cases of post-transfusion non-A non-B hepatitis in patients with thalassemia major. Interferon alfa is an effective treatment for patients with chronic hepatitis C. Response to therapy is related to the duration of treatment, the viral load in serum, and the hepatitis C virus genotype. The purpose of this study was to estimate the response of multitransfused children with beta-thalassemia and chronic hepatitis C to interferon alfa-2b therapy. Thirteen patients with beta-thalassemia and chronic hepatitis C, (mean age+/-SD, 14.1 +/- 1.7 years) participated in the study. Liver biopsy, estimation of HCV RNA, and virus genotyping were performed before onset of treatment. All patients were positive for HCV RNA in a low concentration; two patients carried the la genotype, four had genotype 3, and seven had genotype 4. Patients were treated with 3 x 10(6) U of subcutaneous interferon alfa-2b three times weekly. Eleven of 13 patients received therapy for 18 months; the remaining two underwent therapy for 6 months. Six of 13 patients responded completely to therapy, four responded partially, and three did not respond at all. The grade of inflammation and stage of fibrosis was lower in complete responders. Complete responders had lower ferritin values compared with the values for partial and nonresponders before starting therapy. The results suggest that interferon therapy should be recommended for children with beta-thalassemia major complicated by a low viral concentration of hepatitis C.