Clinical validation of a capnodynamic method for measuring end-expiratory lung volume in critically ill patients.

RATIONALE: End-expiratory lung volume (EELV) is reduced in mechanically ventilated patients, especially in pathologic conditions. The resulting heterogeneous distribution of ventilation increases the risk for ventilation induced lung injury. Clinical measurement of EELV however, remains difficult. OBJECTIVE: Validation of a novel continuous capnodynamic method based on expired carbon dioxide (CO2) kinetics for measuring EELV in mechanically ventilated critically-ill patients. METHODS: Prospective study of mechanically ventilated patients scheduled for a diagnostic computed tomography exploration. Comparisons were made between absolute and corrected EELVCO2 values, the latter accounting for the amount of CO2 dissolved in lung tissue, with the reference EELV measured by computed tomography (EELVCT). Uncorrected and corrected EELVCO2 was compared with total CT volume (density compartments between - 1000 and 0 Hounsfield units (HU) and functional CT volume, including density compartments of - 1000 to - 200HU eliminating regions of increased shunt. We used comparative statistics including correlations and measurement of accuracy and precision by the Bland Altman method. MEASUREMENTS AND MAIN RESULTS: Of the 46 patients included in the final analysis, 25 had a diagnosis of ARDS (24 of which COVID-19). Both EELVCT and EELVCO2 were significantly reduced (39 and 40% respectively) when compared with theoretical values of functional residual capacity (p < 0.0001). Uncorrected EELVCO2 tended to overestimate EELVCT with a correlation r2 0.58; Bias - 285 and limits of agreement (LoA) (+ 513 to - 1083; 95% CI) ml. Agreement improved for the corrected EELVCO2 to a Bias of - 23 and LoA of (+ 763 to - 716; 95% CI) ml. The best agreement of the method was obtained by comparison of corrected EELVCO2 with functional EELVCT with a r2 of 0.59; Bias - 2.75 (+ 755 to - 761; 95% CI) ml. We did not observe major differences in the performance of the method between ARDS (most of them COVID related) and non-ARDS patients. CONCLUSION: In this first validation in critically ill patients, the capnodynamic method provided good estimates of both total and functional EELV. Bias improved after correcting EELVCO2 for extra-alveolar CO2 content when compared with CT estimated volume. If confirmed in further validations EELVCO2 may become an attractive monitoring option for continuously monitor EELV in critically ill mechanically ventilated patients. TRIAL REGISTRATION: clinicaltrials.gov (NCT04045262).

Enigmatic tracks of solitary sauropods roaming an extensive lacustrine megatracksite in Iberia.

Sauropod remains are abundant on the Iberian Peninsula across the Jurassic-Cretaceous transition. Where the osteological record shows a high diversity of this kind of dinosaur, the ichnological findings are mainly limited to sauropod tracks characterized by kidney-shaped manus (with or without pollex impressions) and pes impressions with three claw imprints oriented laterally. Here, we present a new sauropod ichnotaxon, Iniestapodus burgensis, found at several exposures within the Las Sereas megatracksite (Burgos, Spain). These are preserved within lacustrine limestone strata of the Rupelo Formation (Tithonian-Berriasian). Iniestapodus burgensis is characterized by: semicircular manus tracks with small pollex impressions; unusual tetradactyl pes tracks with evidence of four claws oriented anteriorly (I-II) and laterally (III-IV), of variable sizes (short claw I and IV impressions, claw II and III being the largest). The combination of features and comparison with the osteological record allows us to propose a non-titanosaurian titanosauriform as a possible trackmaker. All the Iniestapodus tracks are represented by at least two different size classes of small and medium-sized individuals, and their trackways show different multidirectional orientations. The paleoenvironmental and paleoecological data suggest that Iniestapodus trackmakers were solitary individuals, likely representing different age classes, that crossed and used the Las Sereas shallow lacustrine-palustrine areas as their preferred habitat.

We Need to Know: A Call for Interdisciplinary Education on COVID-19.

COVID-19 disrupted numerous disciplines which led to widespread misinformation on the virus. Thirteen students from across the USA designed a web-based conference, or "webinar," to minimize the misinformation among student populations. Professionals presented the current and possible future impacts of COVID-19 in their respective fields. Pre- and post-conference surveys were administered to the attendees to gauge the impact of the conference. Survey results demonstrated increased knowledge and a lower degree of feeling overwhelmed by COVID-19 information overall, indicating a niche use for webinars during the COVID-19 pandemic and beyond.

Tunable Three-Body Loss in a Nonlinear Rydberg Medium.

Long-range Rydberg interactions, in combination with electromagnetically induced transparency (EIT), give rise to strongly interacting photons where the strength, sign, and form of the interactions are widely tunable and controllable. Such control can be applied to both coherent and dissipative interactions, which provides the potential for generating novel few-photon states. Recently it has been shown that Rydberg-EIT is a rare system in which three-body interactions can be as strong or stronger than two-body interactions. In this work, we study three-body scattering loss for Rydberg-EIT in a wide regime of single and two-photon detunings. Our numerical simulations of the full three-body wave function and analytical estimates based on Fermi's golden rule strongly suggest that the observed features in the outgoing photonic correlations are caused by the resonant enhancement of the three-body losses.

Quantum Interference between Photons from an Atomic Ensemble and a Remote Atomic Ion.

Many remote-entanglement protocols rely on the generation and interference of photons produced by nodes within a quantum network. Quantum networks based on heterogeneous nodes provide a versatile platform by utilizing the complementary strengths of the differing systems. Implementation of such networks is challenging, due to the disparate spectral and temporal characteristics of the photons generated by the different quantum systems. Here, we report on the observation of quantum interference between photons generated from a single ion and an atomic ensemble. The photons are produced on demand by each source located in separate buildings, in a manner suitable for quantum networking. Given these results, we analyze the feasibility of hybrid ion-ensemble remote entanglement generation.

Single nucleotide polymorphisms associated with nonsyndromic cryptorchidism in Mexican patients.

Cryptorchidism is a frequent genitourinary malformation considered as an important risk factor for infertility and testicular malignancy. The aetiology of cryptorchidism is multifactorial in which certain SNPs, capable of inhibiting the development of the gubernaculum, are implicated. We analysed 16 SNPs by allelic discrimination and automated sequencing in 85 patients and 99 healthy people, with the objective to identify the association between these variants and isolated cryptorchidism. In two different patients with unilateral cryptorchidism, we found the variants rs121912556 and p.R105R of INSL3 gene in a heterozygous form associated with cryptorchidism, so we could considered them as risk factors for cryptorchidism. On the other hand, SNPs rs10421916 of INSL3 gene, as well as the variants rs1555633 and rs7325513 in the RXFP2 gene, and rs3779456 variant of the HOXA10 gene were statistically significant, when the patients and controls were compared and could be considered as protective factors since are predominantly present in controls. The genotype-phenotype correlation did not show statistical significance. With these results, we could conclude that these polymorphisms can be considered as important variants in our population and would contribute in the future knowledge of the aetiology and physiopathology of cryptorchidism.

Analgesia multimodal para el postoperatorio en la enfermedad renal crónica: fentanilo transcutáneo, fentanilo oral transmucosa y metamizol / Multimodal analgesia for postoperative pain in the renal failure: Metamizole, oral fentanyl and fentanyl patch

La enfermedad renal crónica (ERC) es una situación clínica cada vez más prevalente. Esto se debe en gran medida al aumento de la esperanza de vida y al incremento de la incidencia de la diabetes mellitus (DM) y la hipertensión arterial (HTA). Estos pacientes requieren un manejo cuidadoso de la analgesia postoperatoria. El fentanilo es un fármaco cuya farmacocinética encaja en el manejo del dolor en la ERC. Sus diferentes presentaciones comerciales permiten elaborar estrategias adecuadas para brindarles una analgesia postoperatoria de gran calidad. Presentamos el esquema de analgesia postoperatoria de un paciente en fallo renal severo sometido a artroplastia de cadera: metamizol (6 gramos/24 horas) en perfusión durante 48 horas, fentanilo transcutáneo TTS 25 microgramos/hora durante 48 horas y fentanilo oral transmucosa 200 microgramos en caso de exacerbación del dolor. Este tratamiento analgésico permitió el control satisfactorio del dolor sin que se presentaran vómitos, prurito ni estreñimiento; la calidad del sueño y el descanso nocturno fueron buenos (AU)

Chronic kidney failure (CKF) is a clinical situation with an increasing prevalence due to the high incidence of hypertension and diabetes both of them considered as risk factors, and also due to the rise on life expectancy. These patients need a carefully anaesthetic management in order not to aggravate their renal function. Postoperative analgesia becomes a key point at this end. Fentanyl´s pharmacokinetic totally fits in handling pain in CKF´s patients. Thanks to the great commercial display on fentanyl´s presentation we are able to develop suitable strategies to offer high quality postoperative analgesia. We describe a case of a severe CKD patient undergoing hip arthroplasty following this analgesia plan during the first 48 hours postoperative: Continuous infusion of metamizol (6 g/24 hours) + transdermal fentanyl (25 µg/h) + transmucosal fentanyl (200 µg) if necessary. With this analgesia approach we obtained a satisfactory pain control without vomits, itching or constipation; the patient had a proper rest at night (AU)

Archimedes' principle in fluidized granular systems.

We fluidize a granular bed in a rectangular container by injecting energy through the lateral walls with high-frequency sinusoidal horizontal vibrations. In this way, the bed is brought to a steady state with no convection. We measured buoyancy forces on light spheres immersed in the bed and found that they obey Archimedes' principle. The buoyancy forces decrease when we reduce the injected energy. By measuring ascension velocities as a function of gamma, we can evaluate the frictional drag of the bed; its exponential dependence agrees very well with previous findings. Rising times of the intruders ascending through the bed were also measured, they increase monotonically as we increase the density.

Vibration-induced granular segregation: a phenomenon driven by three mechanisms.

The segregation of large spheres in a granular bed under vertical vibrations is studied. In our experiments, we systematically measure rise times as a function of density, diameter, and depth, for two different sinusoidal excitations. The measurements reveal that, at low frequencies, inertia and convection are the only mechanisms behind segregation. Inertia (convection) dominates when the relative density is greater (less) than one. At high frequencies, where convection is suppressed, fluidization of the granular bed causes either buoyancy or sinkage and segregation occurs.

Fibrilación ventricular coincidiendo con el uso del bisturí eléctrico durante cirugía laparoscópica / Ventricular fibrillation coinciding with the use of an electric scalpel during laparoscopic surgery

No disponible

Rabdomiólisis y posición sentada para cirugía de fosa posterior / Rhabdomyolisis and seated position for surgery on the posterior fossa

No disponible

A pharmacokinetic and tolerability evaluation of two continuous subcutaneous infusion systems compared to an oral controlled-release morphine.

The pharmacokinetic profiles, safety, and tolerability of continuous subcutaneous infusion with a novel drug deliver system (the MEDIPAD system) was compared to a standard infusion pump (the CADD-Micro) and to controlled-release tablets (MS Contin) for the administration of morphine sulfate. This was a single-center, open-label, three-treatment study conducted in 24 male and female healthy volunteers. The mean age was 40.6 yr (SD = +/- 12.27). A three treatment design was chosen to compare differences between modes of administration within each subject to minimize the impact of intersubject variability: Treatment A was a continuous 48-hr subcutaneous infusion of morphine sulfate (165.6 mg at a rate of 3. 45 mg/hr) with the MEDIPAD system attached to the chest, Treatment B was a series of four oral doses of morphine sulfate (120 mg each) at 12-hr intervals, and Treatment C was a continuous 48-hr subcutaneous infusion of morphine sulfate (163.2 mg at a rate of 3.40 mg/hr) with the CADD-Micro device attached to the chest. Subjects began treatment after eligibility was established and informed consent was obtained. The primary pharmacokinetic parameters (AUC, C(max)) for the two devices were similar; 90% confidence intervals showed that the MEDIPAD system was bioequivalent to the CADD-Micro in terms of both rate and extent of morphine absorption. The mean morphine plasma concentration versus time plot suggested that plasma concentrations rise more rapidly with the MEDIPAD device than with the CADD-Micro or oral administrations. The MEDIPAD system showed mild application and injection site reactions; there were no site reactions for the CADD-Micro or oral doses. As expected nausea, somnolence, and abdominal pain occurred more frequently in the oral treatment than the two infusion devices. These data suggest that the MEDIPAD system, which is currently undergoing clinical evaluation, is an acceptable alternative to the traditional oral treatment of morphine sulfate for delivery of analgesics as it allows rapid absorption of morphine; is small, easy to use, and disposable; and achieves plasma levels that are essentially equal to other standard infusion pumps.

Sinonasal lymphoma.

The clinical course of 49 patients with the diagnosis of non-Hodgkin's lymphoma were studied in the Department of Otolaryngology of the Hospital General de Mexico between December 1986 and March 1997. The most frequent clinical symptoms in these patients were: nasal obstruction, rhinorrhea, fever, weight loss, cervical lymph adenopathy, rhinopharyngeal tumor, ulceration on the palate and periorbital cellulitis. In 73% of the patients in this series the primary presentation was nasal. Sixty-six percent of the patients were classified as intermediate grade lymphoma according to the New Working Formulation, and 33% were in a I B state according to the Ann Arbor predominant immunotype was B cell in 63% of the cases. An extensive review of the literature is also presented.

[Structural and functional changes in the of heart of high-performance (canoeing) athletes]. / Cambios estructurales y funcionales en el corazón del atleta (canotaje) de alto rendimento.

We studied two groups of healthy subjects: Group I was integrated by 13 high-performance sportsmen (10 men and 3 women), devoted to the discipline of the rowing. Group II was integrated by 16 sedentary healthy subjects. All of them were studied with a two-dimensional echocardiogram, in order to study the anatomical and functional characteristics of the heart. Both groups had similar characteristics in regard of total body area, heart rate and blood pressure, the only difference was in age. The ventricular mass and the diastolic volume were greater in athletes in spite of the fact that the dimensions and transverse thicknesses were similar, this imply a longitudinal increase of the heart size. It is possible that this form of ventricular remodeling has functional advantages. On the other hand, it was demonstrated the existence of physiological hypertrophy without disorders in diastolic function.