Sweet-spot operation of a germanium hole spin qubit with highly anisotropic noise sensitivity.

Spin qubits defined by valence band hole states are attractive for quantum information processing due to their inherent coupling to electric fields, enabling fast and scalable qubit control. Heavy holes in germanium are particularly promising, with recent demonstrations of fast and high-fidelity qubit operations. However, the mechanisms and anisotropies that underlie qubit driving and decoherence remain mostly unclear. Here we report the highly anisotropic heavy-hole g-tensor and its dependence on electric fields, revealing how qubit driving and decoherence originate from electric modulations of the g-tensor. Furthermore, we confirm the predicted Ising-type hyperfine interaction and show that qubit coherence is ultimately limited by 1/f charge noise, where f is the frequency. Finally, operating the qubit at low magnetic field, we measure a dephasing time of T 2 * = 17.6 µs, maintaining single-qubit gate fidelities well above 99% even at elevated temperatures of T > 1 K. This understanding of qubit driving and decoherence mechanisms is key towards realizing scalable and highly coherent hole qubit arrays.

Foreign body impaction in the esophagus: are there underlying motor disorders?

RESULTS: Compared with the control group, the impacted subjects presented marked reduction in amplitude and duration of esophageal contraction in the proximal esophagus. CONCLUSIONS: These motor disorders could be responsible for the foreign body impaction in the esophagus. However, we believe this patient group should be further studied by 24-hour esophageal manometry to reach a more accurate diagnosis by studying each patient's entire circadian cycle.

Pedunculated liposarcoma of the esophagus.

Polypoid tumours of the esophagus present diagnostic and therapeutic problems. Liposarcomas are infrequent among them. We report a recent case. A 73-year-old male patient was seen in May 1995 in the Ear, Nose and Throat (ENT) Department, Clinica Modelo de Morón, with intermittent dysphagia and dyspnoea due to recurrent vomiting. A laryngeal lineal tomography showed a subglottic obstruction due to extrinsic compression. The patient was referred to the Gastroenterology Department, where an upper gastrointestinal (upper GI) series demonstrated mega-esophagus with abundant retained food. Endoscopy showed a large intraluminal mass covered by normal mucosa which arose on the posterior wall. Videofluoroscopy and chest CT diagnosed a probable polypoid lipoma due to its densitometric characteristics. The tumour was resected by left cervicotomy and left esophagotomy. The patient's progress to date is favourable. Pathology studies showed a well-differentiated liposarcoma. According to the literature, the first case was reported in 1983, and ours is only the seventh case in the world to be documented.

Current-Controlled Spin Precession of Quasistationary Electrons in a Cubic Spin-Orbit Field.

Space- and time-resolved measurements of spin drift and diffusion are performed on a GaAs-hosted two-dimensional electron gas. For spins where forward drift is compensated by backward diffusion, we find a precession frequency in the absence of an external magnetic field. The frequency depends linearly on the drift velocity and is explained by the cubic Dresselhaus spin-orbit interaction, for which drift leads to a spin precession angle twice that of spins that diffuse the same distance.

Beyond the compact magnetic domain wall.

Domain wall dynamics in wide submicrometer wires is investigated to understand the fundamental mechanisms that limit wall mobility, both experimentally by magneto-optical Kerr effect and by micromagnetic simulations. It is found that the dynamic domain wall structure departs significantly from the current description of a compact entity when evolving along the wire. The wall is composed of several substructures, each one propagating and evolving in a different dynamic regime with very different velocities.

Impact of a chronic care model based on patient empowerment on the management of Type 2 diabetes: effects of the SINERGIA programme.

AIMS: Several chronic care models for diabetes have been implemented in Italy, although conclusive data on their effectiveness are lacking. In the Cusano-Milanino diabetes clinic, patients with Type 2 diabetes with a stable disease/therapy (i.e. a steady level of HbA(1c) without need for therapy changes) are included in the SINERGIA programme: diabetologists, nurses and dietitians empower patients and telemedicine resources are utilized efficiently. METHODS: Clinical outcomes measured in the year before and after the initiation of SINERGIA were compared. A generalized hierarchical linear regression model for repeated measures was used. RESULTS: Altogether, 1004 patients were included; baseline characteristics were (mean ± sd): age 66.6 ± 6.2 years, 54.1% male, diabetes duration 10.8 ± 7.7 years, BMI 29.5 ± 4.8 kg/m(2) , HbA(1c) 6.9 ± 0.9% (52 ± 14 mmol/mol); 72.9% of patients were treated with anti-hypertensive drugs; 32.7% were treated with lipid-lowering drugs. After a median follow-up of 12 months (range 6-24 months), the proportion of patients with HbA(1c) ≤ 7.0% (≤ 53 mmol/mol) increased from 32.7 to 45.8% (P<0.0001), while those with HbA(1c) ≥9% (≥75 mmol/mol) decreased from 10.5 to 4.3% (P<0.0001). Patients with LDL cholesterol <100 mg/dl (<2.59 mmol/l) increased from 40 to 47% (P <0.0001), while those with LDL cholesterol ≥130 mg/dl (≥3.36 mmol/l) decreased from 26.6 to 19.7%; blood pressure levels were slightly improved. The mean number of face-to-face encounters decreased from (median and range) 2.8 (2.3-3.4) to 2.3 (1.9-2.7) (P<0.0001) visits per patient/year. CONCLUSIONS: The SINERGIA model is effective in improving metabolic control and major cardiovascular risk factors, while allowing diabetologists to dedicate more time to patients with more acute disease.

Ferromagnetic imprinting of nuclear spins in semiconductors.

We examine how a ferromagnetic layer affects the coherent electron spin dynamics in a neighboring gallium arsenide semiconductor. Ultrafast optical pump-probe measurements reveal that the spin dynamics are unexpectedly dominated by hyperpolarized nuclear spins that align along the ferromagnet's magnetization. We find evidence that photoexcited carriers acquire spin-polarization from the ferromagnet, and dynamically polarize these nuclear spins. The resulting hyperfine fields are as high as 9000 gauss in small external fields (less than 1000 gauss), enabling ferromagnetic control of local electron spin coherence.

Prevalence, clinical spectrum and atypical symptoms of gastro-oesophageal reflux in Argentina: a nationwide population-based study.

BACKGROUND: Population-based data on gastro-oesophageal reflux in Latin America are lacking. AIM: To assess gastro-oesophageal reflux symptom prevalence, clinical spectrum and association with the atypical symptoms in our country. METHODS: Gastro-oesophageal reflux self-report questionnaires validated at Mayo Clinic, USA, were submitted to a sample of 1000 residents (aged 18-80 years) from 17 representative geographical areas of Argentina. The samples were selected and stratified according to age, gender, geographical areas and size of town of residence provided by the Argentine Bureau of Statistics and Census. RESULTS: The overall prevalence of any typical gastro-oesophageal reflux symptom experienced in the previous year was 61.2% (95% CI, 57.9-64.6), the prevalence of frequent gastro-oesophageal reflux symptoms was 23.0% (95% CI, 20.1-25.9) and the prevalence of gastro-oesophageal reflux disease was 11.9% (95% CI, 9.6-14.1). Frequent gastro-oesophageal reflux symptoms were associated with dysphagia (OR 2.12, 95% CI, 1.27-3.54, P < 0.01), globus (OR 2.22, 95% CI, 1.35-3.66, P < 0.01) and non-cardiac chest pain (OR 1.55, 95% CI, 1.04-2.31, P < 0.05). CONCLUSIONS: In Argentina, typical symptoms of gastro-oesophageal reflux are highly prevalent at the national level, and frequent gastro-oesophageal reflux symptoms are significantly associated with dysphagia, globus and non-cardiac chest pain.

Revision stapes surgery for recurrent transmissional hearing loss after stapedectomy and stapedotomy for otosclerosis.

A total of 20 stapedotomy and 24 stapedectomy cases were retrospectively reviewed to establish the causes of failure, and to evaluate hearing results after revision surgery. Our series included 23 male and 21 female patients. Mean age at revision time was 42 years, and the mean interval from primary surgery and revision stapes surgery was 27 months. The retrospective review of our data, revealed that the most common cause for revision surgery was a displaced prosthesis (47.7%). After revision surgery, the mean post-operative air-bone gap was 14.78 dB. A mean post-operative air-bone gap within 10 dB occurred in 24 patients (54.5%), in 14 patients (31.5%) this was between 11 and 20 dB, in 5 patients (11.5%) between 21 and 30 dB, and in one patient (2.5%) > 30 dB. There were no "dead ears" in this series. Our results compare to other reported series, and confirm that after revision stape surgery, an air-bone gap closure within 10 dB is difficult to obtain. In the present series, the use of the total ossicular replacement prosthesis resulted in the poorest functional hearing results.

Development of arthritis and hypothyroidism during alpha-interferon therapy for chronic hepatitis C.

Alpha-interferon (alpha-IFN) therapy may induce, reveal or exacerbate various autoimmune-related disorders. The most common is the development of autoantibodies, while clinically overt autoimmune diseases are rare. We describe a 49-year-old woman who developed seronegative rheumatoid-like arthritis and autoimmune hypothyroidism after 7 months of human lymphoblastoid alpha-IFN therapy given for hepatitis C virus-related chronic active hepatitis (CAH-HCV). There was no family or personal history of autoimmune, thyroid or articular diseases. Our patient required continuous therapy for arthritis and hypothyroidism despite discontinuation of alpha-IFN. This suggests that alpha-IFN therapy may induce the contemporary appearance of two different persistent autoimmune-related diseases in the same patient. However, chronic HCV infection may play an important adjuvant role in the development of these diseases.

Endoscopic CO2 laser treatment of supraglottic carcinoma.

Aim of the study was to evaluate whether laser endoscopic microsurgery is a reliable and appropriate approach to treatment of laryngeal supraglottic cancer. A retrospective study was made of 12 patients (11 M/1 F; mean age 62.5 years) treated from December 1995 to October 2001 in the Department of Surgical Sciences and Organ Transplantations, Section of Otorhinolaryngology, University of Cagliari, Italy. Surgical steps and oncologic results are reported. These 12 patients with supraglottic cancer underwent transoral laser surgery (TNM classification: T1, 3 patients; T2, 9 patients; N-, 9 patients; N+, 3 patients; M-, 12 patients). On the basis of the different subsites removed, the following resections were performed: 1 limited excisional biopsy (false chord), 3 wide excisional biopsies (2 or 3 subsites), 2 simple epiglottectomies, 1 extended epiglottectomy, 3 horizontal supraglottic laryngectomies, and 2 horizontal supraglottic laryngectomies that were extended to the anterior commissure and to one arytenoid, respectively. Five patients underwent functional neck dissection, and one patient underwent post-operative radiotherapy at sites of tumour and lymph nodes. Temporary tracheotomy was carried out in 10 patients. Mean follow-up was 33.3 months. No local recurrences were noted. Local control was thus 100%. Aspiration was the main post-operative problem, but there were no cases of aspiration-associated pneumonia. Moreover, no patient needed laryngectomy or a permanent tracheotomy for aspiration. In conclusion, although our experience with supraglottic cancers treated by endoscopy is still too limited to confirm the definitive oncologic validity of this type of surgery, in our hands, it seems to be a reasonable tool in selected cases and a safe, time- and cost-effective alternative to traditional surgery or radiotherapy for selected supraglottic carcinomas.

[Gastroesophageal reflux disease refractory to medical treatment. Which approach: the pill or the scalpel?]. / Enfermedad por reflujo gastroesofágico refractaria al tratamiento medico. Qué conducta adoptar: la píldora o el bisturí?

We analyze the modern literature regarding natural history, clinical picture and treatment of gastroesophageal reflux disease. The characteristics of a small group of patients with tendency to relapse are emphasized, analyzing the possibilities offered by pharmacological as well as surgical treatment. Finally, we analyse the current literature of our country situation.

[Esophageal achalasia: what to do, the balloon or the scalpel?]. / Acalasia del esófago: que hacer, el balón o el bisturi?

In this paper we review the different options published in the world literature regarding the treatment of achalasia of the esophagus. It is concluded that pneumatic dilatation and Heller's operation are the only valid possibilities for primary treatment of the disease. The specific indications for each procedure are also being set. The cost analysis in our country is determined, arriving to the conclusion that pneumatic dilation has a direct cost of A$968 (expectant cost up to A$1.144); and laparoscopic Heller's operation A$2.250. Our personal experience on 120 pneumatic dilatations is analyzed and compared with that of the literature, arriving to the conclusion that our results are similar to the ones of the main available papers.

[Barrett s epithelium: clinical review]. / Epitelio de Barrett: revisión clínica.

In this paper we review the literature about regarding etiology, natural history, methods of study and treatment of Barrett's esophagus. Likewise we review our personal experience as well as the one at national level.

[Esophageal achalasia: review of the results after 15 years' experience]. / Acalasia del esófago: revisión de resultados a los quince años de experiencia.

The purpose of this paper is to evaluate the experience acquired along a 15 years period (1971-1985) in the treatment of achalasia of the esophagus. One hundred and fifty six patients were evaluated. The average age was 50.8 years, and the M/F ratio 0.9/1. Dysphagia was present in 100%, regurgitation in 78.2%, weight loss in 61.5%, and chest pain in 50% of the cases, being the main symptoms. Serology for Chagas disease was positive in 21.2% of the patients. When classified by radiologic criteria the groups were: grate I 18.5%, grate II 53.8%, grate III 14.7% and grate IV 12.8%. The high pressure zone was X 23 mmHg (N 14.8 mmHg) pre dilatation. The incidence of vigorous achalasia was 5.7% and the urecholine test was positive in 61.1%. Only 95 patients were submitted to pneumatic dilatation, and this is the group that we shall analyze in detail. We performed 110 dilatations, since 80 patients were dilated once and 15 received 2 dilatations. The high pressure zone post dilatations was X 12.5 mmHg. We obtained good results in 82.1%, regular in 3.1% and bad results in 14.7% of the patients. The morbidity was 4.5% (3 perforations and 2 gastroesophageal reflux), and the mortality 0.9%. There was relapse in 26.3% of the cases. In 53.3% of the patients submitted to a second dilatation we obtained good results. The average hospital stay was 2.5 days, and the follow up X 32.4 months. Thirty nine patients were sent to surgery with good results in 82%, regular in 2.5%, and bad in 15.6%. The morbidity was 15.3% and the mortality 5.1%.(ABSTRACT TRUNCATED AT 250 WORDS)

[Treatment of benign esophageal stenosis by prolonged dilatation: re-evaluation after 15 years]. / Tratamiento de la estenosis benigna del esófago por medio de la dilatación prolongada: re-evaluación a los quince años.

The purpose of this paper is to re-appraise the results of a method for slow continuous dilatation of benign esophageal stenosis comparing previous experience of a decade with that accumulated during the following five-year period. A total of 78 patients were dilated, the average age was 58.1 years, and the M/F dilated, the average age was 58.1 years, and the M/F ratio 3.3/1. Reflux esophagitis was the most frequent etiology when comparing both groups (77.5% and 79.4% respectively). Esophageal hiatus hernia was the most common associated pathology in both groups (83.3% and 87.7% respectively). Gastric analysis showed average values within the limits of normal, 40% of de cases showed a hypersecretion pattern. The mean lower esophageal sphincter pressure was low, and a group of patients showed aperistalsis in more than 50% of the swallows, fact that was thought to be due to esophageal inability to clear the refluxed material. Another important fact was an increase in the frequency of Barrett's epithelium (6.5% to 9.3%). Undoubtedly the most important features were the increase in the number of good results of dilatation (87.7% to 92.3%), the decrease of morbidity (6.1% to 0.7%) and mortality (2% to 0.2%). The follow-up increased from X 27.3 to X 33.8 months.(ABSTRACT TRUNCATED AT 250 WORDS)

[Esophageal lesion caused by drugs]. / Lesión esofágica por drogas.

Two cases of esophageal injury secondary to drugs are hereby presented, reviewing the different types of drugs, predisposing factors, physiopathology and complications.

[Predictive factors in the treatment of esophageal achalasia]. / Factores Predictivos en el Tratamiento de la Acalasia del Esófago.

With aim of determining if there are predictive factors in the treatment of achalasia of the esophagus, we analyzed in a group of 119 patients variables such as age, gender, X-Rays, Chagas' disease serology and esophageal manometry before and after treatment. The only significant factor was the LES pressure post-treatment but, since the sampling was heterogeneous, and the differences where the same between bad and good results, we believe it has no predictive value in the treatment of achalasia of the esophagus.

[Esophageal motility dysfunction and radioisotopes. Its modification with a calcium channel blocker]. / Disfunción motora esogágica y radioisótopos. Su modificación con un bloqueante cálcico.

We described the esophageal radionuclide transit (ERT) of a liquid bolus through 5 areas in pharynx, esophagus (3 levels) and gastric fundus before and after the administration of 30 mg of sublingual nifedipine, in 8 normal individuals and 13 patients with different esophageal motor disturbances. The controls and patients were previously studied by esophageal manometry (EM). The results in control individuals were as follows: 1) the total transit time (TTT) was 11.85 +/- 1.13 sec, 2) the time of beginning of gastric filling (GF) was 3.99 +/- 0.65 sec, 3) the residual activity (RA) was 9.53 +/- 4.64%, 4) nifedipine showed a statistically significant increase of the RA. The ERT detected 100% of the achalasic patients with a TTT that was not greater than 40 seconds and a delayed GF. In the classic achalasia patients nifedipine did not produce significant modifications in the ERT. The only case of vigorous achalasia studied showed an adynamic pattern with activity in peaks which improved after the administration of nifedipine. One of the nutcracker esophagus showed a pattern of sequential peaks with a similar response to nifedipine. The sensitivity of the method was 100%, nifedipine seems to be useful in the sense that improves the esophageal transit. Since the ERT as a non-invasive method and has a 100% sensitivity, we propose it as a step previous to EM in the study of esophageal motor disorders.

[Achalasia of the esophagus]. / Acalasia del esófago.

Thirty-two cases of achalasia of the esophagus are studied in retrospect. The evolution was carried on from different standpoints: clinical, radiological, endoscopic, and motility studies. Patients were treated by dilatation (either pneumatic or mercury bougies) or surgery. The result of treatment was evaluated from the clinical standpoint correlating it with the remaining studies in order to establish wether or not they were related.