Optomechanical Rydberg-atom excitation via dynamic Casimir-Polder coupling.

We study the optomechanical coupling of a oscillating effective mirror with a Rydberg atomic gas, mediated by the dynamical atom-mirror Casimir-Polder force. This coupling may produce a near-field resonant atomic excitation whose probability scales as ∝(d(2)an(4)t)(2)/z(0)(8), where z(0) is the average atom-surface distance, d the atomic dipole moment, a the mirror's effective oscillation amplitude, n the initial principal quantum number, and t the time. We propose an experimental configuration to realize this system with a cold atom gas trapped at a distance ∼2×10 µm from a semiconductor substrate whose dielectric constant is periodically driven by an external laser pulse, hence realizing an effective mechanical mirror motion due to the periodic change of the substrate from transparent to reflecting. For a parabolic gas shape, this effect is predicted to excite about ∼10(2) atoms of a dilute gas of 10(3) trapped Rydberg atoms with n=75 after about 0.5 µs, which is high enough to be detected in typical Rydberg gas experimental conditions.

Bilateral surgical reconstruction for internal jugular veins disease in patients with chronic cerebrospinal venous insufficiency and associated multiple sclerosis.

Chronic cerebrospinal venous insufficiency (CCSVI) is a vascular condition characterized by morphologic alterations involving efferent cerebral vascular paths. CCSVI has been implicated as a contributing factor to multiple sclerosis (MS) but this theory is highly controversial. We report 3 cases of CCSVI patients with MS who had undergone internal jugular veins (IJVs) angioplasty to restore vessels patency. All patients reported significant symptomatic improvement after angioplasty until symptoms recurred after restenosis of the treated IJVs. Surgical IJVs reconstruction was performed. Patients' symptoms gradually improved and the benefits were maintained at the 1-year follow-up.

Thioflavin T hydroxylation at basic pH and its effect on amyloid fibril detection.

The fluorescent dye thioflavin T (ThT) is commonly used for in situ amyloid fibril detection. In this work, we focused on the spectroscopic properties and chemical stability of ThT in aqueous solution as a function of pH, temperature, and dye concentration. A reversible hydroxylation process occurs in alkaline solutions, which was characterized using a combination of UV-vis absorption spectroscopy, proton NMR, and density functional theory (DFT). On the basis of these studies, we propose a chemical structure for the hydroxylated form. Finally, by means of fluorescence spectroscopy, ThT hydroxylation effects on in situ amyloid detection have been investigated, providing new insights on the efficiency of the ThT assay for quantitative fibril evaluation at basic pH.

Perioperative management of a heterozygous carrier of Glanzmann's thrombasthenia submitted to coronary artery bypass grafting with cardiopulmonary bypass.

Glanzmann's thrombasthenia is a congenital hemorrhagic disorder transmitted as an autosomal recessive trait and characterized by altered production and/or assembly of the platelet membrane glycoprotein IIb/IIIa receptor. We describe the perioperative management of a heterozygous carrier of Glanzmann's thrombasthenia submitted to cardiac surgery with cardiopulmonary bypass and the case was complicated by early excessive postoperative bleeding.

Retrograde pulmonary perfusion improves results in pulmonary embolectomy for massive pulmonary embolism.

Mortality rates for pulmonary embolectomy in patients with acute massive pulmonary embolism have decreased in recent years. However, they still range from 30% to 45% when the surgery is performed on critically ill patients, and the rates reach 60% in patients who have experienced cardiac arrest before the procedure. The causes of death in these patients are generally attributed to right heart failure due to persistent pulmonary hypertension, intractable pulmonary edema, and massive parenchymal and intrabronchial hemorrhage. Clinical and experimental findings indicate that venous air embolism causes severe or even lethal damage to the pulmonary microvasculature and the lung parenchyma consequent to the release of endothelium-derived cytokines. These findings are similar to those observed when severely compromised patients undergo pulmonary embolectomy-air entrapped in the pulmonary artery during embolectomy can lead to fatal outcomes. Besides enabling the removal of residual thrombotic material from the peripheral branches of the pulmonary artery, retrograde pulmonary perfusion fills the pulmonary artery with blood and prevents pulmonary air embolism. In this retrospective study, we analyzed a series of 21 consecutive critically ill patients in whom we applied retrograde pulmonary perfusion while performing standard pulmonary embolectomy. No patient died or experienced major postoperative complications. We believe that the use of retrograde pulmonary perfusion decreases morbidity and mortality rates associated with pulmonary embolectomy in critically ill patients.

Venous Hemodynamic Insufficiency Severity Score variation after endovascular treatment of chronic cerebrospinal venous insufficiency.

INTRODUCTION: Chronic cerebrospinal venous insufficiency (CCSVI) is a vascular condition characterized by anomalies of the internal jugular veins (IJVs) and/or azygos veins with disturbed flow and formation of collateral venous channels. The presence of CCSVI has been associated with multiple sclerosis (MS). Percutaneous venous angioplasty (PVA) has been proposed to improve extracranial outflow; however, a non-invasive, post-procedural follow-up outcome measure has not been established. AIM OF THE STUDY: To evaluate the short-term hemodynamic follow-up of CCSVI after PVA using color Doppler ultrasound (CDU) and to investigate whether hemodynamic variation correlated with clinical variation. MATERIALS AND METHODS: Forty-five patients affected by MS with confirmed CCSVI underwent IJVs PVA. Venous hemodynamic (VH) parameters indicative of CCSVI and the Venous Hemodynamic Insufficiency Severity Score (VHISS) were evaluated by CDU at baseline and 3 months post-PVA. Concurrently, the MS-related disability status (EDSS) was evaluated. RESULTS: The VH parameters and VHISS 3 months after IJVs PVA significantly decreased: the VH parameters -32.1% and the VHISS -33.8% (p < 0.001). The EDSS score 3 months after IJVs PVA was significantly lower than the baseline (-5.5%, p < 0.001). Using the median value of the VHISS variation as the cut-off, we were able to identify two groups of patients: responders, group A; and non-responders, group B. The EDSS score variation at 3 months was 0.310 in group A and 0.275 in group B (p = 0.746). CONCLUSIONS: CCSVI endovascular treatment can induce an improvement in VH parameters and the VHISS. The neurological disability score (EDSS) also improved after PVA; however, there was no correlation to the VHISS variation after PVA, MS type and duration.

Vacuum Casimir energy densities and field divergences at boundaries.

We consider and review the emergence of singular field fluctuations or energy densities at sharp boundaries or point-like field sources in the vacuum. The presence of singular energy densities of a field may be relevant from a conceptual point of view, because they contribute to the self-energy of the system. They could also generate significant gravitational effects. We first consider the case of the interface between a metallic boundary and the vacuum, and obtain the structure of the singular electric and magnetic energy densities at the interface through an appropriate limit from a dielectric to an ideal conductor. Then, we consider the case of a nondispersive and nondissipative point-like source of the electromagnetic field, described by its polarizability, and show that also in this case the electric and magnetic energy densities show a singular structure at the source position. We discuss how, in both cases, these singularities give an essential contribution to the electromagnetic self-energy of the system; moreover, they solve an apparent inconsistency between the space integral of the field energy density and the average value of the field Hamiltonian. The singular behavior we find is softened, or even eliminated, for boundaries fluctuating in space and for extended field sources. We discuss in detail the case in which a reflecting boundary is not fixed in space but is allowed to move around an equilibrium position, under the effect of quantum fluctuations of its position. Specifically, we consider the simple case of a 1D massless scalar field in a cavity with one fixed and one mobile wall described quantum-mechanically. We investigate how the possible motion of the wall changes the vacuum fluctuations and the energy density of the field, compared with the fixed-wall case. Also, we explicitly show how the fluctuating motion of the wall smears out the singular behaviour of the field energy density at the boundary.

Hemostatic effects of tranexamic acid in elective thoracic aortic surgery: a prospective, randomized, double-blind, placebo-controlled study.

OBJECTIVE: We studied the hemostatic effects of tranexamic acid in patients undergoing elective surgery involving the thoracic aorta. METHODS: In a double-blind, randomized fashion, 60 consecutive patients were assigned to two treatment groups: 30 patients (placebo group) received infusion of saline solution, and 30 (treatment group) received tranexamic acid (1 g before skin incision, an infusion of 400 mg/h during the operation, and 500 mg in the pump priming). Perioperative bleeding was considered as a primary outcome. Perioperative allogeneic transfusions, major thrombotic complications (myocardial infarction, pulmonary embolism, renal insufficiency), and surgical outcomes were also considered. RESULTS: Patients treated with tranexamic acid showed significant reductions in postoperative bleeding, both in terms of the amount collected during the first 4 postoperative hours (median 307 mL, interquartile range 253-361 mL in the placebo group vs median 211 mL, interquartile range 108-252 mL in the treatment group, P =.002) and in terms of total bleeding (median 722 mL, interquartile range 574-952 mL in the placebo group vs median 411 mL, interquartile range 313-804 mL in the treatment group, P =.04). Consequently, the number of patients transfused differed significantly between groups (21 patients [72.4%] in the placebo group vs 13 [44.8%] in the treatment group, P =.033). Patients in the treatment group showed significant reductions in the total amount for the entire group of packed red cells transfused (13,500 mL in the treatment group vs 28,000 mL in the placebo group, P =.012) and in the total amount of allogeneic transfusions (23,400 mL in the treatment group vs 53,000 mL in the placebo group, P =.024). No differences in perioperative thrombotic complications were found. CONCLUSIONS: In this initial series of patients undergoing thoracic aortic surgery, tranexamic acid appeared effective in reducing perioperative bleeding, with a significant reduction in the need for allogeneic transfusions and without any increased risk of thrombotic complications.

Retrograde pulmonary perfusion as an adjunct to standard pulmonary embolectomy for acute pulmonary embolism.

Mortality rates for pulmonary embolectomy in patients with acute massive pulmonary embolism have decreased in recent years. However, it still ranges from 30 to 45% when surgery is performed on critically ill patients, and the mortality rates reach 60% in patients who have experienced a cardiac arrest before the procedure. The causes of death in these patients are generally attributed to right heart failure due to persistent pulmonary hypertension, intractable pulmonary oedema, and massive parenchymal and intrabronchial haemorrhage. Clinical and experimental findings indicate that venous air embolism causes severe or even lethal damage to the pulmonary microvasculature and the lung parenchyma consequent to the release of endothelium-derived cytokines. These findings are similar to those observed when severely compromised patients undergo pulmonary embolectomy for air entrapped in the pulmonary artery during embolectomy, which may lead to fatal outcomes. Retrograde pulmonary perfusion (RPP), besides enabling the removal of residual thrombotic material from the peripheral branches of the pulmonary artery, fills the pulmonary artery with blood and prevents pulmonary air embolism. We believe that the use of RPP as an adjunct to conventional pulmonary embolectomy decreases the morbidity and mortality rates associated with pulmonary embolectomy in critically ill patients.

Laparoscopic approach for very large benign ovarian cyst in young woman.

Ovarian cysts are the most common cause of pelvic masses in women, and in the majority of the cases, women are in their fertile age. Today, the surgical treatment has become more conservative and less invasive; hence, a laparoscopic approach in the presence of benign cysts has become a gold standard. Herein, we report a case of a 21-year-old woman referred to our Surgical Department for an abdominal mass, discovered with a computerised tomographic scan, of 20x10 x 25cm arising from the left ovary, treated with the laparoscopic approach.

Intraoperative moderate acute normovolemic hemodilution associated with a comprehensive blood-sparing protocol in off-pump coronary surgery.

UNLABELLED: We evaluated the blood-sparing effects of intraoperative moderate acute normovolemic hemodilution (ANH) combined with intraoperative tranexamic acid treatment and shed blood reinfusion in patients undergoing off-pump coronary artery bypass (OPCAB). One-hundred consecutive OPCAB patients (baseline hematocrit >34%) were prospectively randomized to tranexamic acid treatment (control group; 50 patients) or to tranexamic acid treatment plus normovolemic (1:1 replacement with colloids) withdrawal of 17% +/- 2% of the circulating blood volume (ANH group; 50 patients). All patients had shed blood reinfused with intraoperative bleeding in excess of 250 mL. The requirement for allogeneic transfusions, based on strict a priori defined criteria, was the primary end point of the study. Hematochemical evaluations, bleeding, major complications, and other outcomes were also recorded. Demographics, baseline hematochemical data, and operative characteristics were similar in the two groups. Patients in the ANH group had a median of 850 mL of blood withdrawn and showed a lower intraoperative minimum hematocrit (31% vs 37%; P < 0.0001). Two patients in the ANH group versus 10 patients in the control group (odds ratio, 0.17; 95% confidence interval, 0.03-0.89; P = 0.028) required transfusion of a significantly smaller number of packed red blood cell units (5 vs 24; P < 0.001). Postoperative hematochemical variables, bleeding, and outcomes were similar in the two groups of patients. Moderate ANH, combined with tranexamic acid administration and on-demand shed blood reinfusion, may reduce allogeneic transfusion requirements in OPCAB patients. IMPLICATIONS: We studied the blood-sparing effects of moderate acute normovolemic hemodilution (ANH) in 100 patients undergoing off-pump coronary surgery (OPCAB). Combined with tranexamic acid administration and shed blood reinfusion when the intraoperative bleeding exceeded 250 mL, ANH was effective in reducing the number of OPCAB patients who required allogeneic transfusions and the number of packed red blood cell units transfused.

Intraoperative low-volume acute normovolemic hemodilution in adult open-heart surgery.

BACKGROUND: Recently, various studies have questioned the efficacy of intraoperative acute normovolemic hemodilution (ANH) in reducing bleeding and the need for allogeneic transfusions in cardiac surgery. The aim of the present study was to reevaluate the effects of a low-volume ANH in elective, adult open-heart surgery. METHODS: Two hundred four consecutive adult patients undergoing cardiac surgery were prospectively randomized in a nonblinded manner into two groups: ANH group (103 patients), where 5-8 ml/kg of blood was withdrawn before systemic heparinization and replaced with colloid solutions, and a control group, where no hemodilution was performed (101 patients). Procedures included single and multiple valve surgery, aortic root surgery, coronary surgery combined with valve surgery, or partial left ventriculectomy. The purpose of the study was to evaluate the efficacy of ANH in reducing the need for allogeneic blood components. Routine hematochemical evaluations, perioperative blood loss, major complications, and outcomes were also recorded. RESULTS: No differences were found between the groups regarding demographics, baseline hematochemical data, and operative characteristics. There was no difference in the amount of transfusions of packed red cells, fresh frozen plasma, platelet concentrates, total number of patients transfused (control group, 36% vs. ANH group, 34.3%; P = 0.88), and amount of postoperative bleeding (control group, 412 ml [313-552 ml] vs. ANH group, 374 ml [255-704 ml]) (median [25th-75th percentiles]); P = 0.94. Further, perioperative complications, postoperative hematochemical data, and outcomes were not different. CONCLUSIONS: In patients undergoing elective open-heart surgery, low-volume ANH showed lack of efficacy in reducing the need for allogeneic transfusions and postoperative bleeding.