Efficient Unitary Designs with a System-Size Independent Number of Non-Clifford Gates

Many quantum information protocols require the implementation of random unitaries. Because it takes exponential resources to produce Haar-random unitaries drawn from the full n-qubit group, one often resorts to t-designs. Unitary t-designs mimic the Haar-measure up to t-th moments. It is known that Clifford operations can implement at most 3-designs. In this work, we quantify the non-Clifford resources required to break this barrier. We find that it suffices to inject O ( t 4 log 2 ( t ) log ( 1 / ε ) ) many non-Clifford gates into a polynomial-depth random Clifford circuit to obtain an ε -approximate t-design. Strikingly, the number of non-Clifford gates required is independent of the system size - asymptotically, the density of non-Clifford gates is allowed to tend to zero. We also derive novel bounds on the convergence time of random Clifford circuits to the t-th moment of the uniform distribution on the Clifford group. Our proofs exploit a recently developed variant of Schur-Weyl duality for the Clifford group, as well as bounds on restricted spectral gaps of averaging operators.

Forced to join the Waffen-SS? Chief pharmacist Victor Capesius (1907-1985) and his role in Auschwitz concentration camp

Victor Capesius (1907-1985) attained sad fame as chief pharmacist in the Auschwitz concentration camp. After the war he outlined himself as a victim of his time and claimed to have been forced into the Waffen-SS as a so-called Romanian "Volksdeutscher" (ethnic German). But does this claim stand up to critical scrutiny? What was his actual role in Auschwitz, how did his life develop in the postwar period, how did he himself evaluate his actions in the Third Reich, and to what extent do self-image and historical facts coincide? These are precisely the questions that this article explores. The study is based on primary sources from various archives. These are supplemented and compared with the existing literature on Capesius, the role of pharmacists in the Third Reich, and the Auschwitz concentration camp.<br/> The analysis shows that Capesius was not only complicit in the criminal acts in the concentration camp, but directly involved in the systematic killing of thousands of Jewish people - among other things, by dispensing Zyklon B and phenol and by the lethal selection of people at the ramp. The alleged compulsion to join the Waffen-SS, on the other hand, cannot be substantiated. After 1945, Capesius was imprisoned twice by the Allies, but only charged in the first Auschwitz trial in the 1960s. Despite a guilty verdict, he was released from prison as early as 1968. At the end of his life, Capesius could look back on a successful career as a pharmacist and businessman in Germany. At no time did he come to a self-critical evaluation of his role in the Third Reich.

Risk factor heterogeneity for medial and lateral compartment knee osteoarthritis: analysis of two prospective cohorts

OBJECTIVE

To evaluate the etiologic heterogeneity between medial and lateral tibiofemoral radiographic osteoarthritis (ROA).

METHODS

Knees without medial or lateral tibiofemoral ROA at baseline were followed for 60-month in Multicenter Osteoarthritis Study (MOST) and for 48-month in Osteoarthritis Initiative (OAI). We examined the relation of previously reported risk factors to incident medial and lateral tibiofemoral ROA separately and determined the etiology heterogeneity with a ratio of rate ratios (RRs) (i.e., the RR for medial tibiofemoral ROA divided by the RR for lateral tibiofemoral ROA) using a duplication method for Cox proportional hazard regression.

RESULTS

Of 2,016 participants in MOST, 436 and 162 knees developed medial or lateral tibiofemoral ROA, respectively. Obesity and varus malalignment were 95% and 466% more strongly associated with incident medial tibiofemoral ROA than with lateral tibiofemoral ROA, respectively (ratios of RRs, 1.95 [95% confidence interval (CI):1.05-3.62] and 5.66 [95% CI:3.20-10.0]). In contrast, the associations of female sex and valgus malalignment with incident medial tibiofemoral ROA were weaker or in an opposite direction compared with lateral tibiofemoral Osteoarthritis (OA) (ratios of RRs, 0.40 [95% CI:0.26-0.63] and 0.20 [95% CI:0.12-0.34], respectively). Older age tended to show a weaker association with incident medial tibiofemoral ROA than with incident lateral tibiofemoral ROA. No heterogeneity was observed for the relation of race, knee injury, or contralateral knee ROA. These findings were closely replicated in OAI.

CONCLUSION

Risk factor profiles for medial and lateral tibiofemoral ROA are different. These results can provide a framework for the development of targeted prevention and potential treatment strategies for specific knee OA subtypes.

Karl Blumenreuter (1881-1969): Himmler's chief pharmacist and medical supply quartermaster of the SS

The present article elucidates the role and function of SS Gruppenführer Karl Blumenreuter (1881-1969), the leading pharmacist of the SS. The aim is to clarify how he participated in the crimes of the Nazi Party and especially the SS during the "Third Reich" and the extent to which he was brought to justice after 1945. Central elements of the study are based on researched archival primary sources. The latter were compared with each other and supplemented with the currently available secondary literature on the subject. It can be established that Blumenreuter was a zealous National Socialist with marked career ambitions who advanced within the SS to the rank of SS Gruppenführer and Lieutenant General of the Waffen SS (Generalleutnant der Waffen SS). He supplied pre-measured phenol ampoules for the murder of prisoners in the concentration camps. Blumenreuter furthermore organised equipment and material supplies for various experiments on humans. After 1945 he succeeded in playing down his participation in the crimes in the time of National Socialism. Blumenreuter died in 1969 without having being brought to justice by the judiciary and without having reflected self-critically on his role in the "Third Reich".

Recovering Quantum Gates from Few Average Gate Fidelities

Characterizing quantum processes is a key task in the development of quantum technologies, especially at the noisy intermediate scale of today's devices. One method for characterizing processes is randomized benchmarking, which is robust against state preparation and measurement errors and can be used to benchmark Clifford gates. Compressed sensing techniques achieve full tomography of quantum channels essentially at optimal resource efficiency. In this Letter, we show that the favorable features of both approaches can be combined. For characterizing multiqubit unitary gates, we provide a rigorously guaranteed and practical reconstruction method that works with an essentially optimal number of average gate fidelities measured with respect to random Clifford unitaries. Moreover, for general unital quantum channels, we provide an explicit expansion into a unitary 2-design, allowing for a practical and guaranteed reconstruction also in that case. As a side result, we obtain a new statistical interpretation of the unitarity-a figure of merit characterizing the coherence of a process.

Experimental quantum compressed sensing for a seven-qubit system

Well-controlled quantum devices with their increasing system size face a new roadblock hindering further development of quantum technologies. The effort of quantum tomography—the reconstruction of states and processes of a quantum device—scales unfavourably: state-of-the-art systems can no longer be characterized. Quantum compressed sensing mitigates this problem by reconstructing states from incomplete data. Here we present an experimental implementation of compressed tomography of a seven-qubit system—a topological colour code prepared in a trapped ion architecture. We are in the highly incomplete—127 Pauli basis measurement settings—and highly noisy—100 repetitions each—regime. Originally, compressed sensing was advocated for states with few non-zero eigenvalues. We argue that low-rank estimates are appropriate in general since statistical noise enables reliable reconstruction of only the leading eigenvectors. The remaining eigenvectors behave consistently with a random-matrix model that carries no information about the true state.

Quantum compressed sensing can provide a scalable way to characterize quantum states and devices, but has been so far limited to states with quickly decaying eigenvalues. Here the authors show that it can be appropriate even in the general case, demonstrating reconstruction the state of a seven-qubit system.

Prevalence of and factors associated with unprotected anal intercourse with regular and nonregular male sexual partners among newly diagnosed HIV-positive men who have sex with men in China

OBJECTIVES

This study investigated the prevalence of, and multi-dimensional factors associated with, unprotected anal intercourse (UAI) with regular male sexual partners ('regular partners') and nonregular male sexual partners ('nonregular partners') among newly diagnosed HIV-positive men who have sex with men (MSM) in Chengdu, China.

METHODS

A total of 225 newly diagnosed HIV-positive MSM were interviewed using a combined interviewer-computer-assisted method in Chengdu, China.

RESULTS

The prevalence of UAI with regular and nonregular partners since diagnosis was 27.7% and 33.8% among participants reporting having sex with regular and nonregular partners (n = 159 and 133), respectively. Adjusted analysis showed that: (1) cognitive variables based on the Health Belief Model (perceived susceptibility to HIV transmission and perceived severity of the consequences of HIV transmission, perceived barriers and perceived self-efficacy related to consistent condom use), (2) emotion-related variables (worry about transmitting HIV to others), (3) psychological factors (post-traumatic growth) and (4) socio-structural factors (perceived partners' responsibility for condom use) were significantly associated with UAI with regular and/or nonregular partners.

CONCLUSIONS

Interventions are warranted, and should be designed with consideration of multi-dimensional factors and be partner type-specific.

DEEP BIOSPHERE. Exploring deep microbial life in coal-bearing sediment down to ~2.5 km below the ocean floor

Microbial life inhabits deeply buried marine sediments, but the extent of this vast ecosystem remains poorly constrained. Here we provide evidence for the existence of microbial communities in ~40° to 60°C sediment associated with lignite coal beds at ~1.5 to 2.5 km below the seafloor in the Pacific Ocean off Japan. Microbial methanogenesis was indicated by the isotopic compositions of methane and carbon dioxide, biomarkers, cultivation data, and gas compositions. Concentrations of indigenous microbial cells below 1.5 km ranged from <10 to ~10(4) cells cm(-3). Peak concentrations occurred in lignite layers, where communities differed markedly from shallower subseafloor communities and instead resembled organotrophic communities in forest soils. This suggests that terrigenous sediments retain indigenous community members tens of millions of years after burial in the seabed.

Wide cleft between theory and practice: medical students' perception of their education in patient and medication safety

In medicine today, future doctors are expected to ensure patient safety. Yet medical students often feel uncertain if they can meet these high expectations. This study aims to quantify the perceptions of medical students regarding the actual quality of their education in the fields of patient safety and, in particular, medication safety. A questionnaire was designed and distributed to about 100 upper-level medical students. The students had to respond to 12 questions regarding the following categories: 1) familiarity with patient safety and/or medication safety; 2) personal experience in high-risk clinical situations; and 3) perceived relevance of knowledge in the area of patient and medication Safety for clinical practice. Of the respondents 42.1% and 36.8% had delved into the topic patient safety and medication safety, respectively. In clinical practice 88.2% of respondents had experienced a high-risk situation for patients. Regarding patient safety and medication safety, respectively, 82.9% and 85.3% of the respondents found these topics to be particularly relevant to their clinical practice. This study has shown that there is a measurable discrepancy between the students' perceived quality of their medical education and their feelings that they are well prepared to cope with severe clinical challenges.

Unifying framework for relaxations of the causal assumptions in Bell's theorem

Bell's theorem shows that quantum mechanical correlations can violate the constraints that the causal structure of certain experiments impose on any classical explanation. It is thus natural to ask to which degree the causal assumptions-e.g., locality or measurement independence-have to be relaxed in order to allow for a classical description of such experiments. Here we develop a conceptual and computational framework for treating this problem. We employ the language of Bayesian networks to systematically construct alternative causal structures and bound the degree of relaxation using quantitative measures that originate from the mathematical theory of causality. The main technical insight is that the resulting problems can often be expressed as computationally tractable linear programs. We demonstrate the versatility of the framework by applying it to a variety of scenarios, ranging from relaxations of the measurement independence, locality, and bilocality assumptions, to a novel causal interpretation of Clauser-Horne-Shimony-Holt inequality violations.

Matrix-product operators and states: NP-hardness and undecidability

Tensor network states constitute an important variational set of quantum states for numerical studies of strongly correlated systems in condensed-matter physics, as well as in mathematical physics. This is specifically true for finitely correlated states or matrix-product operators, designed to capture mixed states of one-dimensional quantum systems. It is a well-known open problem to find an efficient algorithm that decides whether a given matrix-product operator actually represents a physical state that in particular has no negative eigenvalues. We address and answer this question by showing that the problem is provably undecidable in the thermodynamic limit and that the bounded version of the problem is NP-hard (nondeterministic-polynomial-time hard) in the system size. Furthermore, we discuss numerous connections between tensor network methods and (seemingly) different concepts treated before in the literature, such as hidden Markov models and tensor trains.

Laboratory capability and surveillance testing for Middle East respiratory syndrome coronavirus infection in the WHO European Region, June 2013

Since September 2012, over 90 cases of respiratory disease caused by a novel coronavirus, now named Middle East respiratory syndrome coronavirus (MERSCoV), have been reported in the Middle East and Europe. To ascertain the capabilities and testing experience of national reference laboratories across the World Health Organization (WHO) European Region to detect this virus, the European Centre for Disease Prevention and Control (ECDC) and the WHO Regional Office for Europe conducted a joint survey in November 2012 and a follow-up survey in June 2013. In 2013, 29 of 52 responding WHO European Region countries and 24 of 31 countries of the European Union/European Economic Area (EU/EEA) had laboratory capabilities to detect and confirm MERS-CoV cases, compared with 22 of 46 and 18 of 30 countries, respectively, in 2012. By June 2013, more than 2,300 patients had been tested in 23 countries in the WHO European Region with nine laboratory-confirmed MERS-CoV cases. These data indicate that the Region has developed significant capability to detect this emerging virus in accordance with WHO and ECDC guidance. However, not all countries had developed capabilities, and the needs to do so should be addressed. This includes enhancing collaborations between countries to ensure diagnostic capabilities for surveillance of MERS-CoV infections across the European Region.

Darstellung und Eigenschaften von β-Alkoxypropionsäureestern des Cholesterins

Es werden die Darstellung und die Eigenschaften von β-Alkoxypropionsäure-Cholesterinestern beschrieben und mit denen der entsprechenden Fettsäuren verglichen. Die Schmelzpunkte nehmen mit einer steigenden Zahl von Ätherfunktionen ab. Alle untersuchten Verbindungen durchlaufen die cholesterinische Phase nur beim Abkühlen. Smektische Phasen wurden nicht beobachtet.

Untersuchungen zur Biosynthese der Nicotinsäure bei Mycobacterium tuberculosis

14C-markierte C3-Verbindungen. wie Glycerin, Glycerinaldehyd, Glycerinsäure und Pyruvat werden vorwiegend in den Pyridinring der von Mycobacterium tuberculosis Stamm BCG gebildeten Nicotinsäure eingebaut. Entsprechende Abbauversuche ergeben, daß Glycerin bevorzugt in die C-Atome 4, 5 und 6 der Nicotinsäure inkorporiert wird. Danach erfolgt in diesem Organismus die Biosynthese der Nicotinsäure aus Asparaginsäure und einem C3-Körper wie Glycerin.

3-Hydroxymethylpyridin, ein neues Stoffwechselprodukt der Mycobakterien

Aus dem Kulturfiltrat von Mycobacterium bovis Stamm BCG wird neben Nicotinsäure eine weitere Bromcyan-positive Substanz isoliert und als 3-Hydroxymethylpyridin identifiziert. Dieses Pyridin-Derivat läßt sich auch als Ausscheidungsprodukt anderer Mycobakterien-Arten nachweisen. 3-Hydroxymethylpyridin ist eng mit dem Stoffwechsel der Nicotinsäure verbunden. Angebotene Nicotinsäure wird von den BCG-Bakterien aufgenommen und zu 3-Hydroxymethylpyridin umgewandelt.

Zum Einbau von Trigonellin-[14CT3] in Ricinin

Durch Biosynthese-Untersuchungen mit Trigonellin-[14CH3] an Keimlingen von Ricinus communis wird gezeigt, daß die N-Methylgruppe des Trigonellins abgespalten wird und über den C1-Pool gleichwertig in beide Methylgruppen des Ricinins gelangt. Somit ist ein intakter Trigonellineinbau auszuschließen.

In weiteren Versuchen wird Trigonellin-[14CT3] mit einem bekannten T/14C-Verhältnis an Ricinuskeimlinge verabreicht. Die spezifische T-Einbaurate beträgt nur etwa 30% der 14C-Inkorporation. Sowohl im Ricinin als auch in den beiden Methylgruppen ist das T/14C-Verhältnis auf ein Drittel gegenüber dem Wert des applizierten Trigonellins-[14CT3] reduziert. Dieser Tritiumverlust spricht für eine oxydative Demethylierung des Triginellins und gegen eine echte Transmethylierung.

Self-perceived stigmatization in female patients with anorexia nervosa--results from an explorative retrospective pilot study of adolescents

BACKGROUND

The stigma of mental illness has been identified as an important barrier to treatment and recovery. Previous research reported the stigmatization of individuals with eating disorders by both health professionals and the general public. The aim of this pilot study was to empirically assess the previous stigmatization and discrimination experiences of young female patients with anorexia nervosa (AN) using a retrospective explorative approach.

METHODS

An in-house questionnaire that was developed to survey experiences of stigmatization was mailed to 75 former adolescent patients with AN. The mean time of assessment after discharge was 5.6 ± 1.2 years. The patients were asked to respond anonymously. The response rate was approximately 48% (n = 36).

RESULTS

Feelings that society held negative stereotypes of individuals with AN, concrete experiences of stigmatization and discrimination, and rejection by peers were reported. A remarkable degree of self-stigmatization, as indexed by high rates of agreement to stigmatizing statements, was detected. Approximately one third of the participants reported delayed initiation of treatment due to fear of stigmatization and discrimination.

CONCLUSION

Stigmatization plays a decisive role in young patients with AN and impacts their motivation to seek professional help and engage in treatment. Clinicians should be aware of the stigmatization related to eating disorders and its burden for affected patients.

Scalable reconstruction of density matrices

Recent contributions in the field of quantum state tomography have shown that, despite the exponential growth of Hilbert space with the number of subsystems, tomography of one-dimensional quantum systems may still be performed efficiently by tailored reconstruction schemes. Here, we discuss a scalable method to reconstruct mixed states that are well approximated by matrix product operators. The reconstruction scheme only requires local information about the state, giving rise to a reconstruction technique that is scalable in the system size. It is based on a constructive proof that generic matrix product operators are fully determined by their local reductions. We discuss applications of this scheme for simulated data and experimental data obtained in an ion trap experiment.

Laboratory capability for molecular detection and confirmation of novel coronavirus in Europe, November 2012

A rapid survey by the European Centre for Disease Prevention and Control (ECDC) and the World Health Organization (WHO) Regional Office for Europe ascertained the availability of national reference laboratory testing for a recently detected novel coronavirus as of 28 November 2012. Screening by internal quality controlled upE-RT-PCR assay was available in 23/46 of responding countries in the WHO European Region, of which 19/30 in European Union (EU) and European Economic Area (EEA) countries. Confirmation of positive screened samples by either ORF1b - RT-PCR, or other target RT-PCR assays with sequence analysis or whole-genome sequence analysis was available in 22/46 responding countries of which 18/30 in EU/EEA countries.

Artefacts in CBCT: a review

Artefacts are common in today's cone beam CT (CBCT). They are induced by discrepancies between the mathematical modelling and the actual physical imaging process. Since artefacts may interfere with the diagnostic process performed on CBCT data sets, every user should be aware of their presence. This article aims to discuss the most prominent artefacts identified in the scientific literature and review the existing knowledge on these artefacts. We also briefly review the basic three-dimensional (3D) reconstruction concept applied by today's CBCT scanners, as all artefacts are more or less directly related to it.

Fully Coupled 3-D Modelling of Ferroelectric Polycrystalline Material Behavior

A thermodynamically consistent phenomenological model for the material behavior of polycrystalline ferroelectric ceramics is presented. The internal state of the material is described by two internal state variables. The first one is a second-order texture tensor, determining a simple orientation distribution function (ODF) for the axes of the crystal unit cells. The second is the vector of relative irreversible polarization. The irreversible strains are derived from the ODF by volume averaging. The polarization saturation states are calculated by summing up the possible contributions of all cells to the overall polarization. An invariant formulation of the piezoelectric law is applied. Analogous to the thermodynamical framework of rate-independent plasticity, driving forces and evolution laws for the internal state variables are established. Saturation and coupling of the switching behavior are governed by energy barrier functions introduced in the electric enthalpy function. Numerical examples illustrate the models capabilities.

Permutationally invariant quantum tomography

We present a scalable method for the tomography of large multiqubit quantum registers. It acquires information about the permutationally invariant part of the density operator, which is a good approximation to the true state in many relevant cases. Our method gives the best measurement strategy to minimize the experimental effort as well as the uncertainties of the reconstructed density matrix. We apply our method to the experimental tomography of a photonic four-qubit symmetric Dicke state.

Supersonic quantum communication

When locally exciting a quantum lattice model, the excitation will propagate through the lattice. This effect is responsible for a wealth of nonequilibrium phenomena, and has been exploited to transmit quantum information. It is a commonly expressed belief that for local Hamiltonians, any such propagation happens at a finite "speed of sound". Indeed, the Lieb-Robinson theorem states that in spin models, all effects caused by a perturbation are essentially limited to a causal cone. We show that for meaningful translationally invariant bosonic models with nearest-neighbor interactions (addressing the challenging aspect of an experimental realization) this belief is incorrect: We prove that one can encounter accelerating excitations under the natural dynamics that allow for reliable transmission of information faster than any finite speed of sound. It also implies that the simulation of dynamics of strongly correlated bosonic models may be much harder than that of spin chains even in the low-energy sector.

Most quantum States are too entangled to be useful as computational resources

It is often argued that entanglement is at the root of the speedup for quantum compared to classical computation, and that one needs a sufficient amount of entanglement for this speedup to be manifest. In measurement-based quantum computing, the need for a highly entangled initial state is particularly obvious. Defying this intuition, we show that quantum states can be too entangled to be useful for the purpose of computation, in that high values of the geometric measure of entanglement preclude states from offering a universal quantum computational speedup. We prove that this phenomenon occurs for a dramatic majority of all states: the fraction of useful n-qubit pure states is less than exp(-n;{2}). This work highlights a new aspect of the role entanglement plays for quantum computational speedups.

Selective amygdalohippocampectomy: surgical outcome in children versus adults

INTRODUCTION

The objective of the study was to review our experience with selective amygdalohippocampectomy (SAH) in children and adults with intractable temporal lobe epilepsy.

METHODS

A retrospective case series was used in the setting of a tertiary care hospital which provides epilepsy care to both children and adults. All patients underwent a selective amygdalohippocampectomy procedure and had at least one year of follow-up. Adults and children were divided into two groups and the data was compared between children and adults.

RESULTS

Twenty three patients, 9 children and 14 adults were studied. Age of surgery varied from 6 to 58 years. Surgical outcome was variable between the two groups. Amongst the children, three patients (33%) were seizure-free (Engel Class I), two patients (22%) had rare seizures (Engel Class II), one patient (11%) had a worthwhile decrease in seizures (Engel class III) and three patients (32%) had refractory seizures that required re-operation with an anterior temporal lobectomy. This differed from the adults, who all had a good outcome. Ten patients (71%) were seizure-free (Engel Class I) and the remainder (29%) had rare seizures (Engel Class II).

CONCLUSION

Selective amygdalohippocampectomy can lead to excellent seizure surgical outcome in adults with refractory temporal lobe epilepsy. However, preliminary results show less favorable results in children. The difference is probably related to the different pathology between the two groups. Anterior temporal lobe resection may prove to be a more successful operation than SAH in children with intractable temporal lobe epilepsy.

Novel schemes for measurement-based quantum computation

We establish a framework which allows one to construct novel schemes for measurement-based quantum computation. The technique develops tools from many-body physics-based on finitely correlated or projected entangled pair states-to go beyond the cluster-state based one-way computer. We identify resource states radically different from the cluster state, in that they exhibit nonvanishing correlations, can be prepared using nonmaximally entangling gates, or have very different local entanglement properties. In the computational models, randomness is compensated in a different manner. It is shown that there exist resource states which are locally arbitrarily close to a pure state. We comment on the possibility of tailoring computational models to specific physical systems.

Simulation of discontinuous damage incorporating residual stresses in circumferentially overstretched atherosclerotic arteries

When a balloon-angioplasty is performed, the arterial wall is overstretched and thereby damaged, which leads to a stiffness reduction in the arterial layers. An anisotropic damage model able to reflect the main damage mechanisms in overstretched arterial walls is used in combination with a polyconvex hyperelastic stored energy function. Furthermore, a method for the incorporation of residual stresses present in the wall of unloaded configurations is applied. The energy describes the anisotropic hyperelastic behavior of arteries under physiological conditions. Due to the assumption that the rupture of cross-bridges between collageneous micro-fibrils is responsible for the damage inside arterial walls, the damage function is applied to that part of the energy only which is associated to the fiber elasticity. For the incorporation of the residual stresses into the simulation, we apply a method which consists of two simulation steps. Finally, a numerical simulation of the overstretching of a simplified atherosclerotic artery is performed taking into account residual stresses.

Laparoscopic adrenalectomy

BACKGROUND

Soon after its introduction, laparoscopic adrenalectomy (LA) became the procedure of choice in the surgical management of most adrenal tumors. The aim of this study was to assess the outcome and learning curve of the first 100 cases operated by the same surgical team.

METHODS

Retrospective analysis of prospectively collected data of 100 consecutive LAs was performed. The parameters studied were indication for surgery, side and length of operation, intra- and postoperative complications, size of tumor, conversion to open surgery, final diagnosis, and length of stay.

RESULTS

Between 1996 and 2002, 100 LAs were performed in 90 patients. The procedures included 45 left, 35 right, and 10 bilateral resections for pheochromocytoma (29), Cushings syndrome (27), Conns syndrome (16), nonfunctioning adenoma (13), and others (5). Mean tumor size was 4.16 cm (range, 0.3-11). Overall major morbidity occurred in eight patients (9%); there was one mortality due to cerebrovascular accident in an elderly patient. Five cases (5%) were converted to open surgery. The mean length of stay for the whole group was 4.7 days (range, 2-25). In order to assess the learning curve, procedures were divided into three, equal consecutive groups (n = 33, 33, and 34). Intraoperative complications in the intermediate and late groups were significantly less compared to those in the early group (2/33, 2/34, and 7/33, respectively; (p < 0.05). Similarly, the mean operating time was significantly reduced between the early (169 min) and both intermediate (116 min) and late (127 min) groups (p < 0.005). The conversion rate was reduced between the three groups (3/33, 2/33, and 0/34), but this was not significant (p = 0.06).

CONCLUSIONS

As expected, the outcome of LA is associated with a steep learning curve. According to this study, it seems that performance of approximately 30 cases by an experienced laparoscopic surgeon is required to master the procedure.

Ginseng improves pulmonary functions and exercise capacity in patients with COPD

Ginseng is a root that has been used to treat patients with various illnesses for the last 2000 years. The purpose of this study was to evaluate the effects of Ginseng extract (G115) on Pulmonary Function Tests (PFTs), Maximum Voluntary Ventilation (MVV), Maximum Inspiratory Pressure (MIP) and Maximal Oxygen Consumption (VO2max) in patients with moderately-severe Chronic Obstructive Pulmonary Disease (COPD). Ninety-two adults were randomly divided into the experimental (n = 49, G115 100 mg bid for three months) and placebo-control (n = 43) groups. PFTs, MVV and MIP were studied before treatment and every two weeks for the 3-month-study period. Exercise test and VO2max measurements were performed before the beginning and after six weeks and three months. P lower than 0.05 was considered significant. Baseline demographics and pulmonary parameters were similar between the groups. In the experimental, but not in the control group, all parameters significantly increased above baseline and compared with the placebo group. Maximum increase, compared with baseline was FVC-32.5%, FEV1.0-27.0%, PEF-27.5%, FEF50-45.4%, FEF75-56.9%, MVV-40.4%, MIP-47.0% and VO2max-37.5%. No side effects were observed. G115 100 mg bid for three months, but not placebo, improved PFTs, MVV, MIP and VO2 max in patients with moderately-severe COPD with no side effects.

Post-partum hypocalcemia: idiopatic hypoparathyroidism manifested early in lactation

Hypocalcemia associated with labor and lactation is a rare condition reported previously in patients with hypovitaminosis D. We here describe a case of a young woman in whom symptomatic severe hypocalcemia appeared after her second delivery, early in lactation. At the end of lactation the condition worsened. We review all previously reported cases and suggest a possible physiologic explanation for the association between pregnancy, lactation and the appearance of symptomatic hypocalcemia.