Transport of a Single Cold Ion Immersed in a Bose-Einstein Condensate

We investigate transport dynamics of a single low-energy ionic impurity in a Bose-Einstein condensate. The impurity is implanted into the condensate starting from a single Rydberg excitation, which is ionized by a sequence of fast electric field pulses aiming to minimize the ion's initial kinetic energy. Using a small electric bias field, we study the subsequent collisional dynamics of the impurity subject to an external force. The fast ion-atom collision rate, stemming from the dense degenerate host gas and the large ion-atom scattering cross section, allow us to study a regime of frequent collisions of the impurity within only tens of microseconds. Comparison of our measurements with stochastic trajectory simulations based on sequential Langevin collisions indicate diffusive transport properties of the impurity and allows us to measure its mobility. Our results open a novel path to study dynamics of charged quantum impurities in ultracold matter.

Precision Spectroscopy of Negative-Ion Resonances in Ultralong-Range Rydberg Molecules

The level structure of negative ions near the electron detachment limit dictates the low-energy scattering of an electron with the parent neutral atom. We demonstrate that a single ultracold atom bound inside a Rydberg orbit forming an ultralong-range Rydberg molecule provides an atomic-scale system that is highly sensitive to electron-neutral scattering and thus allows for detailed insights into the underlying near-threshold anion states. Our measurements reveal the so-far unobserved fine structure of the ^{3}P_{J} triplet of Rb^{-} and allows us to extract parameters of the associated p-wave scattering resonances that deviate from previous theoretical estimates. Moreover, we observe a novel alignment mechanism for Rydberg molecules mediated by spin-orbit coupling in the negative ion.

Observation of Rydberg Blockade Induced by a Single Ion

We study the long-range interaction of a single ion with a highly excited ultracold Rydberg atom and report on the direct observation of an ion-induced Rydberg excitation blockade mediated over tens of micrometer distances. Our hybrid ion-atom system is directly produced from an ultracold atomic ensemble via near-threshold photoionization of a single Rydberg excitation, employing a two-photon scheme that is specifically suited for generating a very low-energy ion. The ion's motion is precisely controlled by small electric fields, which allows us to analyze the blockade mechanism for a range of principal quantum numbers. Finally, we explore the capability of the ion as a high-sensitivity, single-atom-based electric field sensor. The observed ion-Rydberg-atom interaction is of current interest for entanglement generation or studies of ultracold chemistry in hybrid ion-atom systems.

Ionic Impurity in a Bose-Einstein Condensate at Submicrokelvin Temperatures

Rydberg atoms immersed in a Bose-Einstein condensate interact with the quantum gas via electron-atom and ion-atom interaction. To suppress the typically dominant electron-neutral interaction, Rydberg states with a principal quantum number up to n=190 are excited from a dense and tightly trapped micron-sized condensate. This allows us to explore a regime where the Rydberg orbit exceeds the size of the atomic sample by far. In this case, a detailed line shape analysis of the Rydberg excitation spectrum provides clear evidence for ion-atom interaction at temperatures well below a microkelvin. Our results may open up ways to enter the quantum regime of ion-atom scattering for the exploration of charged quantum impurities and associated polaron physics.

C-reactive protein and echocardiography have little impact on risk stratification in never-treated hypertensive patients

The aim of this study was to assess the contribution of increased concentrations of high-sensitivity C-reactive protein (hsCRP) and echocardiography to risk stratification according to the 2003 European guidelines for the management of arterial hypertension in patients with untreated hypertension. A total of 207 consecutive medical outpatients with untreated hypertension were included. History and clinical examination, electrocardiography, laboratory analyses including the measurement of hsCRP and echocardiography were performed in all patients. Patients were classified into four risk groups with and without using echocardiography and hsCRP concentrations of at least 10 mg/l according to the 2003 guidelines for the management of hypertension. The majority of the 207 patients (81%) were at moderate or high cardiovascular risk before adding echocardiography and/or hsCRP to the risk stratification process. When echocardiography was included, only three patients were reclassified from the moderate added risk to the high added risk group. Adding hsCRP concentrations of at least 10 mg/l had no impact on risk stratification. Using an hsCRP cutoff level of 3 mg/l, one patient was at moderate instead of low added risk, eight patients were at high instead of moderate added risk and one patient was at very high instead of high added risk. We conclude that hsCRP at the proposed cutoff level of 10 mg/l has no impact on risk stratification in outpatients with untreated hypertension. An hsCRP cutoff level of 3 mg/l may be more suitable for risk stratification. Finally, our data suggest that depending on the population studied, there is minimal impact of echocardiography on risk stratification.

In vivo high-efficiency transcoronary gene delivery and Cre-LoxP gene switching in the adult mouse heart

High-efficiency somatic gene transfer in adult mouse heart has not yet been achieved in vivo. Here, we demonstrate high-efficiency in vivo transcoronary gene delivery to the adult murine myocardium using a catheter-based technique with recombinant adenovirus (AdV) and adeno-associated virus (AAV) vectors in normal and genetically engineered mice. The method involves immersion hypothermia followed by transient aortic and pulmonary artery occlusion with proximal intra-aortic segmental injection of cardioplegic solution containing substance P and viral vectors. Gene expression measured using a LacZ marker gene was observed throughout both ventricles. The expression efficiency of a cytoplasmic LacZ marker gene in the left ventricular myocardium was 56.4+/-14.5% (mean+/-s.d.) at 4 days with an AdV vector, and with an AAV vector it was 81.0+/-5.9% at 4 weeks. Following AAV gene transfer, no gene expression was found in kidney, brain, lung, and spleen, but there was slight expression in liver. In addition, we demonstrate temporally controlled genetic manipulation in the heart with an efficiency of 54.6+/-5.2%, by transferring an AdV vector carrying Cre recombinase in ROSA26 flox-LacZ reporter mice. Procedure-related mortality was 16% for AdV and zero for AAV transfer. Thus, this method provides efficient, relatively homogeneous gene expression in both ventricles of the adult mouse heart, and offers a novel approach for conditional gene rescue or ablation in genetically engineered mouse models.

[Hypertensive emergency]

Hypertensive emergencies are acute, life-threatening events, characterised by high blood pressure and concomitant acute hypertensive target organ damage. These patients need immediate lowering of blood pressure mostly with parenteral drugs in the range of the autoregulative capacity of organ circulation and in-hospital monitoring of the vital functions. Hypertensive urgencies are not necessarily life-threatening, but persistence of high blood pressure may lead to acute target organ damage. Blood pressure should be lowered within 24 to 48 hours. Oral therapy is normally sufficient and hospitalisation is rarely necessary, but maintenance of antihypertensive therapy outside the hospital has to be ascertained.

Relation between insufficient response to antihypertensive treatment and poor compliance with treatment: a prospective case-control study

OBJECTIVES

To prospectively compare compliance with treatment in patients with hypertension responsive to treatment versus patients with treatment resistant hypertension.

DESIGN

Prospective case-control study.

SETTING

Outpatient department in a large city hospital in Switzerland, providing primary, secondary, and tertiary care.

PARTICIPANTS

110 consecutive medical outpatients with hypertension and taking stable treatment with at least two antihypertensive drugs for at least four weeks.

MAIN OUTCOME MEASURES

Treatment compliance assessed with MEMS devices; blood pressure determined by 12 hour daytime ambulatory monitoring (pressure <135/85 mm Hg in patients aged 60 indicated hypertension responsive to treatment).

RESULTS

Complete data were available for 103 patients, of whom 86 took >/=80% of their prescribed doses ("compliant") and 17 took <80% ("non-compliant"). Of the 49 patients with treatment resistant hypertension, 40 (82%) were compliant, while 46 (85%) of the 54 patients responsive to treatment were compliant.

CONCLUSION

Non-compliance with treatment was not more prevalent in patients with treatment resistant hypertension than in treatment responsive patients.

Community-acquired pneumonia--which patients are hospitalised?

BACKGROUND AND OBJECTIVE

Patients with community-acquired pneumonia can be allocated into low and high-risk mortality groups by simple clinical criteria. We studied the value of the stratification for outcome as proposed by Fine, et al. to guide the decision for in-hospital versus outpatient treatment in the emergency department.

PATIENTS AND METHODS

We studied demographic data, risk group stratification and decision-making for in-hospital versus outpatient treatment in 101 consecutive medical emergency department patients with community-acquired pneumonia. We also analysed predictive factors for hospitalisation of low-risk patients. We obtained complete 30 day follow-up information.

RESULTS

Forty-three of 44 high-risk patients were hospitalised after medical emergency department triage. Twenty-seven (47%) of 57 low-risk patients were hospitalised as well. Based on routine clinical assessment, hospitalisation of low-risk patients was required for poor medical condition or severe pneumonia (67%), for lack of social support (15%) and for relevant comorbidity (18%). In an univariate analysis, age (p = 0.003), C-reactive protein (p = 0.0006), presence of comorbidity (p = 0.0001), Charlson index (p = 0.0001) and active oral steroid treatment (p = 0.028) were significantly correlated with hospitalisation of low-risk patients. The 30-day mortality rate was 32% in patients allocated to the high-risk group at the time of diagnosis in the emergency department, compared to 0% in low-risk patients.

CONCLUSION

Simple clinical criteria distinguish well between low and high 30-day-mortality risk in patients diagnosed with community-acquired pneumonia. Nevertheless, 47% of low-risk patients require in-hospital treatment. Age, C-reactive protein, presence of comorbidity and steroid treatment are significantly correlated with hospitalisation of low-risk patients with community-acquired pneumonia.

Community-acquired pneumonia--which patients are hospitalised?

BACKGROUND AND OBJECTIVE

Patients with community-acquired pneumonia can be allocated into low and high-risk mortality groups by simple clinical criteria. We studied the value of the stratification for outcome as proposed by Fine, et al. to guide the decision for in-hospital versus outpatient treatment in the emergency department.

PATIENTS AND METHODS

We studied demographic data, risk group stratification and decision-making for in-hospital versus outpatient treatment in 101 consecutive medical emergency department patients with community-acquired pneumonia. We also analysed predictive factors for hospitalisation of low-risk patients. We obtained complete 30 day follow-up information.

RESULTS

Forty-three of 44 high-risk patients were hospitalised after medical emergency department triage. Twenty-seven (47%) of 57 low-risk patients were hospitalised as well. Based on routine clinical assessment, hospitalisation of low-risk patients was required for poor medical condition or severe pneumonia (67%), for lack of social support (15%) and for relevant comorbidity (18%). In an univariate analysis, age (p = 0.003), C-reactive protein (p = 0.0006), presence of comorbidity (p = 0.0001), Charlson index (p = 0.0001) and active oral steroid treatment (p = 0.028) were significantly correlated with hospitalisation of low-risk patients. The 30-day mortality rate was 32% in patients allocated to the high-risk group at the time of diagnosis in the emergency department, compared to 0% in low-risk patients.

CONCLUSION

Simple clinical criteria distinguish well between low and high 30-day-mortality risk in patients diagnosed with community-acquired pneumonia. Nevertheless, 47% of low-risk patients require in-hospital treatment. Age, C-reactive protein, presence of comorbidity and steroid treatment are significantly correlated with hospitalisation of low-risk patients with community-acquired pneumonia.

Effects of losartan titrated to Losartan/Hydrochlorothiazide and amlodipine on left ventricular mass in patients with mild-to-moderate hypertension. A double-blind randomized controlled study

To study the effects of the angiotensin II receptor antagonist Losartan and Amlodipine on left ventricular mass (LVM), we performed blood pressure measurements and transthoracic echocardiographies at baseline. After a 4-week placebo run-in period, 25 patients with mild-to-moderate essential hypertension were randomly allocated to active treatment with Losartan 50 mg titrated to Losartan 50 mg/hydrochlorothiazide (HCT) 12.5 mg (n = 11) or Amlodipine 5 mg titrated to 10 mg (n = 14) for 16 weeks. After treatment, blood pressure decreased significantly in both groups. LVM and LVM index (mean +/- SD/median) in the Losartan group at baseline were 311 +/- 101/288 g and 163 +/- 55/150 g/m(2) and decreased significantly to 252 +/- 25/255 g and 133 +/- 22/128 g/m(2) (p = 0.003 for LVM; p = 0. 01 for LVM index) after 16 weeks of active treatment. In the Amlodipine group LVM and LVM index decreased from 259 +/- 47/243 g and 136 +/- 25/ 131 g/m(2) to 240 +/- 42/234 g and 126 +/- 24/123 g/m(2) (n.s.). In conclusion, LVM decreased significantly as early as 16 weeks after initiation of antihypertensive treatment with the Angiotensin II antagonist Losartan.

Accuracy and 'range of uncertainty' of oscillometric blood pressure monitors around the upper arm and the wrist

BACKGROUND

Although they have been marketed widely, few data about the diagnostic accuracy of blood pressure monitors are available.

METHODS

Repeated measurements of blood pressures in 85 patients were performed in random sequence with two oscillometric blood pressure monitors around the upper arm (Visomat OZ2) and the wrist (Omron R3( and with a standard sphygmomanometer. The oscillometric blood pressure monitors were validated according to protocols of the British Hypertension Society (BHS) and the American Association for the Advancement of Medical Instrumentation (AAMI). Subsequently, sensitivity and specificity of these monitors for the diagnosis of hypertension or exclusion of the possibility of its presence in a general medical outpatient population were calculated.

RESULTS

Sphygmomanometric readings exceeded oscillometric blood pressure measurements by 3.7+/-7.5/4.8+/-5.6 mmHg (systolic/diastolic) for the upper arm and 5.7+/-6.2/6.8+/-6.8 mmHg for the wrist. Deviations occurred in both directions and were higher for blood pressures in the hypertensive range. Oscillometric blood pressure measurements at the upper arm, but not at the wrist, satisfied validation criteria of BHS and AAMI protocols. Optimal sensitivity and specificity for the diagnosis of hypertension, defined as blood pressure > 140/90 mmHg with a standard sphygmomanometer, was achieved with blood pressure limits of 133/82 mmHg for the Visomat OZ and 131/80 mmHg for the Omron R3.

CONCLUSIONS

Average sphygmomanometer values exceed oscillometrically measured blood pressure values but individual disagreements cannot be predicted. Measurements at the upper arm are more accurate than are those at the wrist according to the validation protocols of the BHS and AAMI. Additional appraisal of sensitivities and specificities and of a 'range of uncertainty' for the diagnosis of hypertension may allow better judgement of accuracy of individual oscillometric blood pressure measurements.