Effects on venous flow of transcutaneous electrical stimulation, neuromuscular stimulation, and sham stimulation on soleus muscle: A randomized crossover study in healthy subjects.

BACKGROUND: Activation of venous flow has been shown with different types of electrical stimulation. The aim of this study is to compare the hemodynamic effects of transcutaneous electrical nerve stimulation (TENS), neuromuscular electrical stimulation (NMES), and sham stimulation on healthy young people. METHODS: This randomized crossover study was conducted during June 2018 in the Faculty of Physical Therapy of A Coruña (Spain). Twenty-four university students (50% male) received in a randomized order 5 Hz-TENS, NMES, and sham stimulation on soleus muscle. Flow volume (FV) and peak velocity (PV) from popliteal vein were recorded via Doppler ultrasound, and relative changes from baseline were determined. Discomfort among the 3 stimulations was also compared. RESULTS: The differences among the 3 stimulations were assessed using the ANOVA for repeated measured, the Friedman test and the Kendall tau test, according to the type of measurement to be compared. FV (mL/min) and PV (cm/s) increased significantly after NMES (percentual increase 37.2 ± 62.0%, P = .002; 264.4 ± 152.2%, P < .001, respectively) and TENS (226.2 ± 190.3%, P < .001; 202.7 ± 144.6%, P < .001, respectively). These percentual changes from basal level in hemodynamics were statistically different to those after placebo, which was ineffective enhancing hemodynamics. The improvements in FV were statistically higher with TENS than with NMES (P < .001), but there was no statistical difference in PV (P = .531). Despite NMES was applied at a significantly lower amplitude than TENS (P < .001), NMES protocol was the worst tolerated, though the differences in discomfort were not statistically significant. CONCLUSION: Both active electrical protocols but not sham stimulation increased hemodynamics in healthy people. TENS obtained higher flow volume increase from baseline than NMES, considered globally at not only in its on-time.

Validity and Reliability of an Offline Ultrasound Measurement of Bladder Base Displacement in Women.

The effect of different exercises on the position of pelvic organs in women has not been sufficiently assessed. The objective was to analyze the validity and reliability of a new two-dimensional ultrasound algorithm to measure offline the displacement of the bladder base during abdominal exercises. This algorithm could be a useful method to future studies in determine the most appropriate exercises in sports and in rehabilitative program for the pelvic floor in women. All subjects were tested by transverse transabdominal ultrasound. The measurements were conducted offline using a customized code written in MATLAB (Ecolab) for image-processing, and manually on the ultrasound monitor using electronic calipers. The agreement was assessed with a paired t-test, Pearson's linear correlation coefficient (r), the Lin's concordance correlation coefficient (CCC), the intraclass correlation coefficient ICC (A,2) and a Bland-Altman plot. The reliability was confirmed by the interdays intra-rater ICC coefficient. The results were that Ecolab and ultrasound transducer measures did not differ statistically (p = 0.246). Furthermore, both methods showed a very strong relationship, and the Ecolab demonstrated to be a valid and reliable method. We concluded that Ecolab seemed to be a valid and reliable tool to assess the effect of abdominal contractions in the female pelvic floor.

Transabdominal ultrasound to assess the displacement of the bladder base during abdominal and pelvic floor contractions in continent parous versus nulliparous women.

INTRODUCTION AND HYPOTHESIS: The effect of different abdominal contractions on the position of pelvic organs in parous women during postpartum exercises has not been sufficiently assessed. The aim of this study was to evaluate the displacement of the bladder base (BB) during different pelvic floor and abdominal contractions in parous women compared to nulliparous women. We hypothesised that abdominal and perineal contractions will produce a disparate effect on the position of the BB between groups. METHODS: Cross-sectional study including a convenience sample of 63 volunteers (35 nulliparous vs. 28 postpartum women). Transabdominal ultrasound was used in mode B to image the displacement of the BB. The protocol included six different pelvic floor and abdominal contractions commonly used in postpartum rehabilitation. RESULTS: The BB elevated significantly more in the postpartum group compared to nulliparous women when performing submaximal contraction of pelvic floor and transversus abdominis muscles simultaneously with axial elongation of the back (0.93 ± 0.55 cm in parous women vs. 0.66 ± 0.46 cm in nulliparous women). In contrast, the BB was found to descend significantly during a curl-up contraction in both groups (0.93 ± 0.55 cm in parous women vs. 0.66 ± 0.46 cm in nulliparous women). CONCLUSIONS: The overall results of this study showed that perineal and superficial abdominal contractions produced different immediate effects compared to deep abdominal contractions on the displacement of BB in parous and nulliparous women. Further research is required to assess the long-term effects of these contractions.

Correction: A product-limit estimator of the conditional survival function when cure status is partially known.

An error was detected in the derivation of the expression of the cumulative hazard function in a recently published paper by Safari, W. C., López-de-Ullibarri, I., and Jácome, M. A. (2021), A product-limit estimator of the conditional survival function when cure status is partially known. Biometrical Journal, 63(5), 984-1005, https://doi.org/10.1002/bimj.202000173. This short article aims to correct this error. There are some changes in the model notation in Section 2, the derivation of the expression of the cumulative hazard function in the Appendix, and the proofs of Lemmas 3 and 4 in the Supporting Information. Moreover, there is a small change in the generation of the values of the censoring variable C ∗ in the simulation study. As a consequence, the simulation results in Section 4 are affected. A corrected version of these sections is given in the Supporting Information.

Characterization and anaerobic digestion of highly concentrated Mexican wine by-products and effluents.

Wine production has increased in recent years, especially in developing countries such as Mexico. This increase is followed by an increase of winery effluents that must be treated to avoid environmental risks. However, little information is available about the characteristics of these effluents and the possible treatments. This paper aimed to characterize the effluents and by-products generated by the Mexican winery industry and to evaluate the performance and stability of the anaerobic treatment using a single-stage and a two-stage process. Results showed that the winery effluents had a high content of biodegradable organic matter, with chemical oxygen demand (COD) values ranging from 221 to 436 g COD/L. The single-stage anaerobic process was able to treat an organic loading rate of 9.6 kg COD/(m3 d); however, it was unstable and highly dependent on the addition of bicarbonate alkalinity (0.31 g NaHCO3/g COD removed). The two-stage process was more stable working at a higher organic load (12.1 kg COD/(m3 d)) and was less dependent on the addition of bicarbonate (0.17 g NaHCO3/g COD removed). The results highlight the potential of the winery effluents to produce methane through anaerobic digestion in a two-stage process, making wine production more sustainable.

Morphological changes in the porcine cervix: A comparison between nulliparous and multiparous sows with regard to post-cervical artificial insemination.

In recent decades, new artificial insemination (AI) methods, such as post-cervical AI (PCAI), have been developed in pig. PCAI involves crossing the cervix to deposit the sperm in the uterine body. Although PCAI application in sows is frequent, its application in nulliparous (gilts) females it is still limited due to the difficulty of passing through the cranial part of the cervical lumen. We hypothesized that ageing and parity would modify the cervical canal, facilitating the introduction of AI devices through the cervix. The aim was to compare the morphology of the uterus at different levels between multiparous and nulliparous females. Morphological analysis of the uterus pointed to a longer cervix (25.9 ±â€¯4.6 vs. 21.6 ±â€¯3.3 cm, p < 0.001) and greater length of the part of the reproductive tract involved in PCAI (from rima vulvae to the last cervical cushion) (56.2 ±â€¯6.0 vs. 50.3 ±â€¯5.2 cm, p < 0.001) in multiparous sows compared with nulliparous animals. As regards the structure of the vaginal and uterine parts of the cervix (the part in contact with the vagina and uterine body, respectively), the cross-sectional area, perimeter and total thickness were greater in the uterine part of multiparous than of nulliparous animals (area: 4.07 ±â€¯1.46 vs. 2.46 ±â€¯0.56 cm2, p < 0.01; perimeter: 8.50 ±â€¯1.44 cm vs. 6.28 ±â€¯0.92 cm, p < 0.001; thickness: 10.79 ±â€¯0.96 vs. 8.35 ±â€¯0.62 mm, p < 0.05), but not in the vaginal part. The tissue content analysed in histological cross-sections also showed differences between female groups, a greater content of connective tissue (58.86 ±â€¯10.78 vs. 67.60 ±â€¯13.38%, p < 0.001) and a lower amount of muscle fibres (39.79 ±â€¯10.24 vs. 30.66 ±â€¯13.69%, p < 0.001) being observed in multiparous sows. Finally, silicone casts of the cervical lumen revealed differences between the two groups in the size and shape of the ridges in the lumen trajectory. Parity, which is also influenced by ageing, determines important changes in the size, structure and tissue content of the cervix wall, as well as in the morphology of the cervical canal, which may be responsible for the different levels of performance of PCAI in the female populations. Therefore, the future design of AI strategies and catheters should take into consideration the morphological variations of the cervix lumen, which will depend on age and parity of the females.

Effects of transcutaneous electrical nerve stimulation via peroneal nerve or soleus muscle on venous flow: A randomized cross-over study in healthy subjects.

BACKGROUND: Transcutaneous electrical nerve stimulation (TENS) is used to prevent venous stasis and thromboembolism. However, best electrostimulation parameters have yet to be established. The aim of the study was to compare the hemodynamic effects and the participants' relative discomfort of 3 TENS sequences at the maximum tolerated intensity stimulus. METHODS: Twenty-four healthy university students (50% male) participated in a cross-over, randomized study. Each participant received 2 TENS sequences on peroneal nerve at 1 and 5 Hz, and the third one on soleus muscle at 5 Hz. Popliteal flow volume (FV) and peak velocity (PV) were measured using Doppler ultrasound and the relative change from basal values was recorded. Discomfort questionnaires -visual analogue scale (VAS) and verbal rating scale (VRS)- were also administered to compare sensations among the three applications. RESULTS: All interventions produced significant hemodynamic responses compared to baseline. Both 5 Hz applications obtained higher FV increments than 1 Hz TENS (P < .001). The muscle application resulted in the lowest PV increment (P < .001). TENS at 5 Hz on nerve location was the worst tolerated, with higher values in VRS (P = .056) and VAS (P = .11), although not significant. CONCLUSION: TENS at 5 Hz on soleus site may be the most appropriate protocol for enhancing venous return.

Comparing conditional survival functions with missing population marks in a competing risks model.

In studies involving nonparametric testing of the equality of two or more survival distributions, the survival curves can exhibit a wide variety of behaviors such as proportional hazards, early/late differences, and crossing hazards. As alternatives to the classical logrank test, the weighted Kaplan-Meier (WKM) type statistic and their variations were developed to handle these situations. However, their applicability is limited to cases where the population membership is available for all observations, including the right censored ones. Quite often, failure time data are confronted with missing population marks for the censored observations. To alleviate this, a new WKM-type test is introduced based on imputed population marks for the censored observations leading to fractional at-risk sets that estimate the underlying risk for the process. The asymptotic normality of the proposed test under the null hypothesis is established, and the finite sample properties in terms of empirical size and power are studied through a simulation study. Finally, the new test is applied on a study of subjects undergoing bone marrow transplantation.

Liver metastasis of ethmoid sinus adenocarcinoma.

INTRODUCTION: Sinonasal cancer is an uncommon neoplasm, often associated with exposure to occupational hazards and delayed diagnosis. CASE REPORT: The authors report a rare case of solitary liver metastasis from ethmoid sinus adenocarcinoma treated by surgical resection. No clinical or radiological sign of recurrence was observed with a follow-up of 3 months. DISCUSSION: Adenocarcinoma of the ethmoid sinus is characterized by its aggressiveness and its tendency to recurrence. Metastases are rare and can be found in unexpected organs due to dissemination via collateral venous plexuses. The role of chemotherapy has not been clearly established. Due to their rarity, the treatment of metastases has not yet been defined.

Logrank-type tests with presmoothing.

The logrank test is the most popular choice for testing the equality of two survival distributions with time-to-event data. It is based on the comparison of the Nelson-Aalen estimates of the corresponding cumulative hazard functions. The improvements of the logrank test in the literature have been accomplished using weighted logrank tests, with the weight chosen appropriately to maximize power. Notwithstanding, power also depends on the efficiency of the estimation of the cumulative hazard function. The presmoothed estimator has been shown to be more efficient than the Nelson-Aalen estimator under some general assumptions. We introduce a new logrank-type test that, instead of the Nelson-Aalen estimator, is based on its presmoothed counterpart. An extensive simulation study has been conducted to compare the performance of this new test with the classical one. This study shows that the new test has the proper size under the null hypothesis, while improving the power over a wide range of alternatives. The new test is illustrated with several real data examples.

DOTS strategy and community participation: an experience in the Ecuadorian Andes.

SETTING: The Chine community in Angamarca parish, Cotopaxi Province, in the Ecuadorian Andes. OBJECTIVE: To relate the DOTS strategy to the world view of the indigenous community in the diagnosis and treatment of smear-positive pulmonary tuberculosis (TB) patients. DESIGN: Cross-sectional study involving all inhabitants of Chine. RESULTS: Aspects of the community's world view were considered in the community-based application of DOTS. A cure rate of 100% was attained, with 0% defaulting from treatment. CONCLUSION: The results obtained indicate that involving the world view of the community in the management of tuberculosis has several advantages.

Highly quasi-monodisperse ag nanoparticles on titania nanotubes by impregnative aqueous ion exchange.

Silver nanoparticles were homogenously dispersed on titania nanotubes (NT), which were prepared by alkali hydrothermal methodology and dried at 373 K. Ag(+) incorporation was done by impregnative ion exchange of aqueous silver nitrate onto NT. First, Ag(+) ions incorporate into the layers of nanotube walls, and then, upon heat treatment under N(2) at 573 and 673 K, they migrate and change into Ag(2)O and Ag(0) nanoparticles, respectively. In both cases, Ag nanoparticles are highly dispersed, decorating the nanotubes in a polka-dot pattern. The Ag particle size distribution is very narrow, being ca. 4 +/- 2 nm without any observable agglomeration. The reduction of Ag(2)O into Ag(0) octahedral nanoparticles occurs spontaneously and topotactically when annealing, without the aid of any reducing agent. The population of Ag(0) nanoparticles can be controlled by adjusting the annealing temperature. An electron charge transfer from NT support to Ag(0) nanoparticles, because of a strong interaction, is responsible for considerable visible light absorption in Ag(0) nanoparticles supported on NT.

Influence of synthesis methods on tungsten dispersion, structural deformation, and surface acidity in binary WO3-ZrO2 system.

WO3-ZrO2 catalysts were synthesized by precipitating the aqueous solutions of zirconium oxynitrate and ammonium metatungstate with ammonium hydroxide. The white slurry precipitate was treated under three different conditions. In the as-made materials, the amorphous phase was formed in the aged and refluxed samples, while well-crystallized tetragonal and monoclinic phases were obtained in the hydrothermally treated sample. The real amount of tungsten loaded in the samples was similar for the three samples, independently of the treatments; however, the tungsten surface atomic density in the annealed WO3-ZrO2 samples varied between 6 and 9 W atoms/nm2. Two different contrast types of aggregates were determined by scanning electron microscopy, the white particles which are rich in W, and the gray ones which are rich in zirconium; both of them were formed in the calcined solids prepared under aging or reflux condition. A very high dispersion of tungsten species on the zirconia surface was achieved in the hydrothermally treated sample. The degree of the interaction between WO(x) and ZrO2 surface strongly modified the Zr-O bond lengths and bond angles in the structure of tetragonal zirconia as proved by X-ray diffraction analysis and the Rietveld refinement. The catalyst obtained under hydrothermal condition exhibited the highest dispersion of tungsten species in the zirconia, which in turn causes strong structural deformation of the tetragonal ZrO2 phase responsible of the strongest surface acidity and, consequently, the optimum catalytic activity for n-hexane isomerization.

Effects of the SO4 groups on the textural properties and local order deformation of SnO2 rutile structure.

Sulfated tin oxide was synthesized from a hydroxylated tin oxide obtained by the precipitation method, followed by ion exchange of OH groups by SO4 species with a sulfuric acid solution. The samples were characterized by X-ray diffraction, transmission electron microscopy, thermoanalysis, and nitrogen physisorption by the Brunauer-Emmett-Teller method. The rutile crystalline structure was refined by the Rietveld method. Thermal analysis suggests the following stoichiometric formulas: SnO2-x(OH)2x and SnO2-x(OH)x(HSO4)x with X = 0.35 and 0.17 for non-sulfated and sulfated samples, respectively. The SO4 species remained strongly bonded at the SnO2 surface stabilizing its crystallite size against sintering, inhibiting the crystallite aggregation, and it acts as a structure porogen director mediating nanoparticle growth and assembly yielding a mesostructure form of SnO2 with wormhole morphology and high thermal stability. The interaction between SO4(2-) and the SnO2 surface changes the symmetry of the representative tin-oxygen octahedron. It relaxes the four tin-oxygen bond lengths located at the basal plane of the octahedron while the two apical Sn-O bonds decrease, producing a strong deformed octahedron, which could be transformed into a higher asymmetry in the electronic distribution around the Sn4+ nuclei. The elimination of SO4 groups brings about the coalescence and crystallite growth, which collapse the mesostructure form of SnO2, decreasing the surface area and porosity.