Slight Contraction Research Articles

Spawning aggregations act as a bottleneck influencing climate change impacts on a critically endangered reef fish

AbstractAimMost projections of how climate change will affect species distributions and phenology are based on a species’ most conspicuous life stage. However, not all life stages are equally sensitive to temperature. Among fishes, spawning adults often have narrower thermal tolerances than other life stages and may constrain population responses to climate change. We tested this hypothesis using data on Nassau Grouper (Epinephelus striatus), an endangered coral reef fish.LocationGreater Caribbean.MethodsSpecies distribution models of spawning and nonspawning adults were compared to determine which environmental variables exerted the greatest influence on grouper distribution. We calculated the thermal niche and ecological niche breadth of both life stages. An earth system model was applied to project how species distribution and phenology shift under two climate change scenarios.ResultsSea surface temperature and seasonal temperature gradients affected the distribution of both spawning and nonspawning adults, but these life stages differed in their preferred temperatures and reaction to oceanic currents. While the two life stages exhibited similar ecological niche breadth, the thermal niche of spawners was narrower. By 2081–2100, potential spawning habitat was projected to decline under a business‐as‐usual scenario by 82% relative to 1981–2000, whereas suitable habitat for nonspawners decreased by 46%. Poleward shifts in latitude occurred 3.8–4.2 times faster for spawners than nonspawners. These changes were attributed to rising temperatures, whereas hydrographical changes did not have a substantial impact. Spawning phenology changed little, with a slight contraction in spawning season but a large reduction in spawning probability across all months.Main ConclusionsA narrow thermal tolerance range among spawning fishes indicates that this life stage may be a bottleneck constraining responses to climate change. Future research should consider the reaction of each life stage to changing conditions. Conservation of E. striatus should take shifting distribution and phenology into account, as climate effects may exacerbate population declines due to fishing and reduce the efficacy of conservation measures.

Body language: Its importance for communication with horses

Body language is important for communication between individuals. Body language is based on the fact that the thought of performing a known action, alone, will activate the motor neurons used for the action, resulting in a slight contraction of the involved muscles. These contractions are called intention movements and signal what the sender will do within the next second, enabling the recipient to react. This type of communication is important both for animals and for peoples' interaction with animals. For example, for social animals, body language communication during competitive situations may prevent subsequent physical interaction making life in the social group more peaceful. Domestic animals that have frequent contact with people learn to read human body language. Similarly, experienced animal trainers learn to read the body language of their animals. This exchange of information makes it safer and more efficient to work with horses. The subtleties of body language may also influence results of scientific studies. Research on preferences or cognitive abilities in horses often use choice experiments combined with operant conditioning. Recent studies have thus demonstrated that horses prefer larger quantities of food than smaller quantities, that they have prospective memory, and that they can communicate with people using symbols. These results may be true, but because the experimental horses are handled by people right before they make their choice within the experiment, it is not possible to determine whether their choice is their own or whether it has been influenced by the body language of the handlers. To be valid, this kind of experiment must eliminate any possibility of human influence. In conclusion, better awareness of horses' body language as well as our own body language makes work with horses easier, safer, and more efficient. Furthermore, creating an environment in which foals and young horses are properly socialized will prepare them for an adult life in a social group, something that is a prerequisite for acceptable horse welfare.

Hopkins syndrome following the first episode of bronchial asthma associated with enterovirus D68: a case report

BackgroundHopkins syndrome (HS) is a rare disorder presenting with acute flaccid paralysis of the limbs following an asthma attack. Neurologists encounter a diagnostic challenge if patients without a history of bronchial asthma develop neurologic features mimicking HS following acute respiratory distress. We report a case of HS occurring after a first episode of bronchial asthma associated with enterovirus D68 infection.Case presentationA 5-year-old girl developed acute respiratory distress. On the fourth hospital day, both her legs became paralyzed except for slight muscle contraction in the right lower limb. Tendon reflexes in the lower limbs were diminished and there was a positive Babinski sign on the right. Sensation was normal in all modalities, and there was no uro-rectal disturbance. Spinal magnetic resonance imaging identified T2-hyperintense lesions with spinal cord edema, mainly involving the bilateral T11 to L1 anterior horns, with left side dominance extending to the left posterior horn. The neurological and neuro-radiological findings of our case were suggestive of HS; however, she had no history of bronchial asthma. An acetylcholine inhalation challenge eventually proved the presence of reversible airway hyper-responsiveness, allowing us to diagnose HS. We identified enterovirus D68 in the patient’s intratracheal aspirates using a sensitive polymerase chain reaction assay. Intravenous immunoglobulin administrations at 2 g/kg2 for 5 consecutive days were repeated every month up to four times. After these treatments, the muscle strength of her right lower limb slightly improved while her left lower leg remained completely paralyzed.ConclusionThis case emphasizes the importance of provocation tests to reveal the presence of airway hyper-responsiveness when a child shows neurological signs mimicking HS following acute respiratory distress. Furthermore, the present case suggests a possible link between HS and acute flaccid paralysis following lower respiratory tract infection by enterovirus D68.

Electronic Structure and Reactivity of One-Electron-Oxidized Copper(II) Bis(phenolate)–Dipyrrin Complexes

The sterically hindered bis(phenol)-dipyrrin ligands HLH3 and PhLH3 were reacted with 1 equiv of copper(II) under ambient conditions to produce the copper radical complexes [Cu(HL)] and [Cu(PhL)]. Their X-ray crystal structures show relatively short C-O bond distances (mean bond distances of 1.287 and 1.291 Å), reminiscent of mixed pyrrolyl-phenoxyl radical species. Complexes [Cu(HL)] and [Cu(PhL)] exhibit rich electronic spectra, with an intense near-IR (NIR) band (ε > 6 mM-1 cm-1) at 1346 and 1321 nm, respectively, assigned to a ligand-to-ligand charger-transfer transition. Both show a reversible oxidation wave ( E1/21,ox = 0.05 and 0.04 V), as well as a reversible reduction wave ( E1/21,red = -0.40 and -0.56 V versus ferrocenium/ferrocene, respectively). The cations ([Cu(HL)]+ and [Cu(PhL)]+) and anions ([Cu(HL)]- and [Cu(PhL)]-) were generated. They all display an axial ( S = 1/2) signal with a copper hyperfine structure in their electron paramagnetic resonance spectra, consistent with ligand-centered redox processes in both reduction and oxidation. Complex [Cu(HL)](SbF6) was cocrystallized with [Cu(HL)]. Oxidation is accompanied by a slight contraction of both the C-O bonds (mean bond distance of 1.280 Å) and the C-C bonds connecting the peripheral rings to the dipyrrin. The cations show vis-NIR bands of up to 1090 nm due to their quinoidal nature. The anions do not show a significant band above 700 nm, in agreement with their bis(phenolate)-dipyrrin character. The radical complexes efficiently catalyze the aerobic oxidation of benzyl alcohol, 1-phenylethanol, and unactivated 2-phenylethanol in basic conditions.

S14-2. F wave and spinal excitability; masseteric contraction or motor imagery enhances ulnar nerve F wave

We tested the validity of instructing patients to clench the teeth to facilitate F-waves recorded from a limb muscle in clinical practice. We explored to study effect of motor imagery and voluntary contraction of the masseter muscles on F waves recorded from the first dorsal interosseous muscle in healthy subjects. F waves were recorded at rest, during motor imagery and during voluntary contraction monitored by a force transducer to maintain the level at 10% of maximal effort. F-wave persistence increased from at rest to during motor imagery, and during voluntary contraction. The trial average of F-waves increased from at rest to during motor imagery and during voluntary contraction. The F-wave latency revealed no significant changes. We have previously shown that motor imagery or slight voluntary contraction of the target muscle enhances F-wave persistence. The current study indicates the same process involving a non-target muscle can also cause a transient increase in distant motoneuron excitability, similar to Jendrassik maneuver. Central drive directed to the masseteric motoneurons can enhance the excitability of ulnar nerve anterior horn cells as evidenced by an increase of trial average of F-wave amplitudes.

QCM-D Investigation of Swelling Behavior of Layer-by-Layer Thin Films upon Exposure to Monovalent Ions.

Polyelectrolyte multilayers and layer-by-layer assemblies are susceptible to structural changes in response to ionic environment. By altering the salt type and ionic strength, structural changes can be induced by disruption of intrinsically bound ion pairs within the multilayer network via electrostatic screening. Notably, high salt concentrations have been used for the purposes of salt-annealing and self-healing of LbL assemblies with KBr, in particular, yielding a remarkably rapid response. However, to date, the structural and swelling effects of various monovalent ion species on the behavior of LbL assemblies remain unclear, including a quantitative view of ion content in the LbL assembly and thickness changes over a wide concentration window. Here, we investigate the effects of various concentrations of KBr (0 to 1.6 M) on the swelling and de-swelling of LbL assemblies formed from poly(diallyldimethylammonium) polycation (PDADMA) and poly(styrene sulfonate) polyanion (PSS) in 0.5 M NaCl using quartz-crystal microbalance with dissipation (QCM-D) monitoring as compared to KCl, NaBr, and NaCl. The ion content after salt exchange is quantified using neutron activation analysis (NAA). Our results demonstrate that Br- ions have a much greater effect on the structure of as-prepared thin films than Cl- at ionic strengths above assembly conditions, which is possibly caused by the more chaotropic nature of Br-. It is also found that the anion in general dominates the swelling response as compared to the cation because of the excess PDADMA in the multilayer. Four response regimes are identified that delineate swelling due to electrostatic repulsion, slight contraction, swelling due to doping, and film destruction as ionic strength increases. This understanding is critical if such materials are to be used in applications requiring submersion in chemically dynamic environments such as sensors, coatings on biomedical implants, and filtration membranes.

Structural Change and Energy Use in China: A SAM-based CGE Analysis

This article presents a structuralist computable general equilibrium (CGE) model for China based on a three productive activities—agriculture, energy and industry—social accounting matrix. Four simulation exercises are conducted using this model: industrial investment demand increase, industrial wage increase, exchange rate depreciation, and government spending increase in industry. Our results show that structural change associated with raising industrial labor productivity and employment-share are likely to result in simultaneous intensification of per worker energy-use and a slight reduction of energy productivity in China. Industrial wage increase creates cost-push inflation and output contraction, and exchange rate devaluation is expansionary. Furthermore, when the industrial exports are insensitive to relative price changes, currency devaluation becomes contractionary and wage increase results in a slight contraction in real GDP due to the “forced saving” effect. The model illustrates some policy challenges China faces in its attempt to achieve “green growth” objectives with a high level of employment.

Half metallicity and pressure-induced electronic structure of monolayer FeX2 (X = S, Se)

In this paper, we present the electronic structure and magnetic properties of two members of transition metal dichalcogenides (TMD) family, FeS2 and FeSe2 compounds, in two dimensional monolayer form (2H) using first principles density functional calculations. Iron dichalcogenide compounds are not an intensively studied group of materials within TMDs, although they have an intrinsic magnetic moment and a large variety electronic properties like metallic, half metallic, and semiconducting in equilibrium and under strain. We find that FeS2 system is found to be metallic in equilibrium and turns into a half-metal, with vanishing density of states of minority spins at Fermi level, at an in-plane pressure of ≈13.7 kbar which corresponds to the slight contraction of the lattice. FeSe2 is an intrinsic half-metal both in equilibrium and under strain in a wide pressure range up to ≈56 kbar. Both structures have increased magnetic moments of 2.00 under pressure compared to their equilibrium phases in which FeS2 and FeSe2 have 1.56 and 1.98 magnetic moments, respectively. Half-metallic gaps in minority spin channels are surrounded by localized Fe-d states in all the systems. The bands crossing Fermi level in majority spins are due to d-states of Fe and p-states of S or Se atoms. Spin–orbit effects are not remarkable on the electronic structure of these systems.

Interplay of upper and lower motor neuron degeneration in amyotrophic lateral sclerosis

ObjectiveWe studied motor unit recruitment to test a new method to identify motor unit firing rate (FR) variability. MethodsWe studied 68 ALS patients, with and without upper neuron signs (UMN) in lower limbs, 24 patients with primary lateral sclerosis (PLS), 13 patients with spinal cord lesion and 39 normal subjects. All recordings were made from tibialis anterior muscles of normal strength. Subjects performed a very slight contraction in order to activate 2 motor units in each recording. 5–7 motor unit pairs were recorded in each subject. Mean consecutive differences (MCD) were calculated for each pair of potentials. The mean MCD for each muscle was estimated as the mean from the total number of pairs recorded. Ap value<0.01 was accepted as significant. ResultsMCD of FR frequency was less in the subjects with spinal cord lesion and PLS. In addition, the FR frequency of the 1st motor unit in a pair of units was markedly reduced in PLS, and in subjects with spinal cord lesions. ConclusionThese results support a lower threshold and reduced FR fluctuation in spinal motor neurons of spastic patients. SignificanceThis method can be developed for detection of UMN lesions.

ZABURZENIA MIĘŚNI UCHA ŚRODKOWEGO JAKO PRZYCZYNA CHOROBY MENIERE'A

The symptoms of Meniere’s disease form a distinct cluster: bouts of vertigo, fluctuating hearing loss, low-frequency tinnitus, and a feeling of pressure in the ear. Traditionally, these signature symptoms have pointed to some sort of pathology within the inner ear itself, but here the focus is shifted to the middle ear muscles. These muscles, the tensor tympani and the stapedius, have generally been seen as serving only a secondary protective role in hearing, but in this paper they are identified as vigilant gate-keepers – constantly monitoring acoustic input and dynamically adjusting hearing sensitivity so as to enhance external sounds and suppress internally generated ones. The case is made that this split-second adjustment is accomplished by regulation of inner ear pressure: when the middle ear muscles contract they push the stapes into the oval window and increase the pressure of fluids inside the otic capsule. In turn, hydraulic pressure squeezes hair cells, instantly adjusting their sensitivity. If the middle ear muscles should malfunction – such as from cramp, spasm, or dystonia – the resulting abnormal pressure will disrupt hair cells and produce Meniere’s symptoms. A wide-ranging review of Meniere’s disease and the middle ear muscles reinforces the link between the two. Since every striated muscle is prone to dystonia – an involuntary contraction involving derangement of its underlying control loop – middle ear muscle dystonia would lead to elevated pressure and abnormal hair cell function. The hypothesis is based on recognizing that the inner ear is a hydrostat – a cavity filled with fluid whose pressure is controlled by the middle ear muscles. Since the fluid is incompressible, even a slight contraction of the muscles can increase the pressure in the labyrinth to 3 kPa. The effect of such a pressure on the sensing cells within is crucial. Outer hair cells carry an internal turgor pressure of about 1 kPa, behaving physically like inflated balloons, and hence contraction of the middle ear muscles can instantly overcome internal cellular pressure, switch off ion channels, and reduce hearing sensitivity. This paper brings together supporting evidence and sets out major implications for Meniere’s disease, including possible treatments.

Corticospinal excitability of the biceps brachii is shoulder position dependent.

The purpose of this study was to examine the effect of shoulder position on corticospinal excitability (CSE) of the biceps brachii during rest and a 10% maximal voluntary contraction (MVC). Participants (n = 9) completed two experimental sessions with four conditions: 1) rest, 0° shoulder flexion; 2) 10% MVC, 0° shoulder flexion; 3) rest, 90° shoulder flexion; and 4) 10% MVC, 90° shoulder flexion. Transcranial magnetic, transmastoid electrical, and Erb's point stimulation were used to induce motor-evoked potentials (MEPs), cervicomedullary MEPs (CMEPs), and maximal muscle compound potentials (Mmax), respectively, in the biceps brachii in each condition. At rest, MEP, CMEP, and Mmax amplitudes increased (P < 0.01) by 509.7 ± 118.3%, 113.3 ± 28.3%, and 155.1 ± 47.9%, respectively, at 90° compared with 0°. At 10% MVC, MEP amplitudes did not differ (P = 0.08), but CMEP and Mmax amplitudes increased (P < 0.05) by 32.3 ± 10.5% and 127.9 ± 26.1%, respectively, at 90° compared with 0°. MEP/Mmax increased (P < 0.01) by 224.0 ± 99.1% at rest and decreased (P < 0.05) by 51.3 ± 6.7% at 10% MVC at 90° compared with 0°. CMEP/Mmax was not different (P = 0.22) at rest but decreased (P < 0.01) at 10% MVC by 33.6 ± 6.1% at 90° compared with 0°. EMG increased (P < 0.001) by 8.3 ± 2.0% at rest and decreased (P < 0.001) by 21.4 ± 4.4% at 10% MVC at 90° compared with 0°. In conclusion, CSE of the biceps brachii was dependent on shoulder position, and the pattern of change was altered within the state in which it was measured. The position-dependent changes in Mmax amplitude, EMG, and CSE itself all contribute to the overall change in CSE of the biceps brachii.NEW & NOTEWORTHY We demonstrate that when the shoulder is placed into two common positions for determining elbow flexor force and activation, corticospinal excitability (CSE) of the biceps brachii is both shoulder position and state dependent. At rest, when the shoulder is flexed from 0° to 90°, supraspinal factors predominantly alter CSE, whereas during a slight contraction, spinal factors predominantly alter CSE. Finally, the normalization techniques frequently used by researchers to investigate CSE may under- and overestimate CSE when shoulder position is changed.

Synergistic effect of fluoride and laser irradiation for the inhibition of the demineralization of dental enamel.

Both laser irradiation and fluoride treatment alone are known to provide increased resistance to acid dissolution. CO2 lasers tuned to a wavelength of 9.3 μm can be used to efficiently convert the carbonated hydroxyapatite of enamel to a much more acid resistant purer phase hydroxyapatite (HAP). Further studies have shown that fluoride application to HAP yields fluoroapatite (FAP) which is even more resistant against acid dissolution. Previous studies show that CO2 lasers and fluoride treatments interact synergistically to provide significantly higher protection than either method alone, but the mechanism of interaction has not been elucidated. We recently observed the formation of microcracks or a "crazed" zone in the irradiated region that is resistant to demineralization using high-resolution microscopy. The microcracks are formed due to the slight contraction of enamel due to transformation of carbonated hydroxyapatite to the more acid resistant pure phase hydroxyapatite (HAP) that has a smaller lattice. In this study, we test the hypothesis that these small cracks will provide greater adhesion for topical fluoride for greater protection against acid demineralization.

Alkali-assisted hydrothermal route to control submicron-sized nanoporous carbon spheres with uniform distribution

Carbon microspheres with nanoporous structures were synthesized based on hydrothermal reaction of saccharide solutions in the presence of potassium hydroxide. The influence of synthesis conditions, including types of saccharide, content of alkali, concentration and reaction time of saccharide solution, on the morphology of the microspheres was systematically investigated, with emphasis on controlling the microsphere size and understanding the role of alkali in hydrothermal reaction. The results show that the microspheres with regular spherical shapes and high surface areas around 500m2g−1 are obtained. The morphology of the microspheres can be tailored by changing the synthesis conditions. The mean diameter of the microspheres varies from 0.16 to 5.61μm. At different stages of the hydrothermal reaction of starch solution, alkali exhibits entirely different effects: (i) to slow the initial hydrolysis of starch, and (ii) to accelerate the subsequent polymerization of dehydrated and fragmented products and the growth of the microspheres. As a result, the competition between the hydrolysis kinetics and the polymerization and growth kinetics plays a critical role in the changes of the morphology and yield of the microspheres. The alkali in dilute starch solution (0.073–0.219M) promotes the increase of the size and yield of the microspheres. In contrast, the alkali in concentrated starch solution (0.292M) results in the reduction and the more uniform distribution of the size of the microspheres with almost constant yield. Note that this alkali assisted hydrothermal route can endow the microspheres with more surface functional groups, including hydroxyl and carboxyl groups, compared with the typical hydrothermal route without alkali. In addition, the formation of the stacks of graphene sheets and the decrease of functional groups occur in the microspheres during pyrolysis, which are accompanied by a significant weight loss of about 50% and a slight contraction in scale.

Observation of compound semiconductors and heterovalent interfaces using aberration-corrected scanning transmission electron microscopy

Abstract

Polyelectrolyte Gel Swelling and Conductivity vs Counterion Type, Cross-Linking Density, and Solvent Polarity

A joint theoretical and experimental study is devoted to the swelling and electrical conductivity of highly charged polyelectrolyte (PE) gels in media of different polarity. Deprotected poly(tert-butyl carbamate l-alanine) gels provided with fluorine, bromine, chlorine, sulfate, and trifluoroacetic counteranions demonstrated different conductivity in aqueous medium as well as solvent uptake in water/methanol mixtures. Counterion specificity in PE gel properties was theoretically explained in the framework of the model which treats ion association within the network as a two-stage process. Manning-type condensation, being the first condensation stage not affected by counterion type, provides understanding of a gel maximal swelling at intermediate degrees of gel ionization f and a slight gel contraction at f tending to unity, which were earlier observed in experimental investigations. The second ion association stage is an ion pairing influenced by the kind of counterion. Since a considerable fraction of io...

Activation of bitter taste receptors (tas2rs) relaxes detrusor smooth muscle and suppresses overactive bladder symptoms.

Bitter taste receptors (TAS2Rs) are traditionally thought to be expressed exclusively on the taste buds of the tongue. However, accumulating evidence has indicated that this receptor family performs non-gustatory functions outside the mouth in addition to taste. Here, we examined the role of TAS2Rs in human and mouse detrusor smooth muscle (DSM). We showed that mRNA for various TAS2R subtypes was expressed in both human and mouse detrusor smooth muscle (DSM) at distinct levels. Chloroquine (CLQ), an agonist for TAS2Rs, concentration-dependently relaxed carbachol- and KCl-induced contractions of human DSM strips. Moreover, 100 μM of CLQ significantly inhibited spontaneous and electrical field stimulation (EFS)-induced contractions of human DSM strips. After a slight contraction, CLQ (1 mM) entirely relaxed carbachol-induced contraction of mouse DSM strips. Furthermore, denatonium and quinine concentration-dependently decreased carbachol-induced contractions of mouse DSM strips. Finally, we demonstrated that CLQ treatment significantly suppressed the overactive bladder (OAB) symptoms of mice with partial bladder outlet obstruction (PBOO). In conclusion, we for the first time provide evidence of the existence of TAS2Rs in the urinary DSM and demonstrate that TAS2Rs may represent a potential target for OAB. These findings open a new approach to develop drugs for OAB in the future.

Effect of additions of Ca compounds to the filling powder on the reduction of MgO and the critical current density properties of ex situ processed MgB2 tapes

We have studied the effect of additions of Ca compounds, CaC2 and CaH2, to the filling powder on the transport critical current density (Jc) properties of ex situ processed MgB2 tapes. These additives are expected to reduce MgO present in as-received commercial MgB2 powder and improve the grain coupling of MgB2 in the tapes. Heat treatment of the hand mixed powders, MgB2 and the Ca compounds, brings about both disappearance of MgB4 and formation of CaB6 and Mg, compared with heat treated MgB2 powder. They are observed much more clearly for the mixtures with CaH2 addition. The MgO content decreases by the additions of those compounds. Neither of the a-axis and the c-axis parameters of MgB2 are changed by the additions, suggesting no reactions of substitutions of Ca for Mg and C for B in MgB2. The Jc properties of the tape samples using the hand mixed filling powder with CaC2 addition degrade, whereas those with CaH2 addition are slightly improved. When using the ball milled mixtures, slight contraction of the a-axis parameter occurs only by CaC2 addition. Although the additions cause the reactions similar to those observed for the hand mixed powders, the MgO content reduces more clearly, compared with the MgB2 content. The Jc properties of the tapes are enhanced in the high-field and low-field regions by the additions of CaC2 and CaH2, respectively. These enhancements are attributed to the carbon substitution, the improved grain coupling and the increased content of MgB2.

A spatiotemporal analysis of tropical cyclone tracks in the Atlantic Basin and their relationship to El Niño-Southern Oscillation

There has been an enhanced focus on Atlantic tropical cyclone climatologies with the significant cyclones of the past decade and the associated loss of life and property. This study examines the geographic location of cyclone tracks and their relationship to El Niño-Southern Oscillation (ENSO). The average annual cyclone track latitude and longitude correlate positively with hurricane-season El Niño indices, indicating that during El Niño conditions, tropical cyclone tracks are shifted northward and eastward. June–November indices explain 11–22% and 3–11% of the variance in cyclone track latitude and longitude, respectively. Examination of the strongest and weakest El Niño years yields similar results. Higher sea level pressure over North America, a slight contraction of the Bermuda High, and a slight decrease in 500 mb heights during El Niño years helps to explain the observed northward and eastward movement of tropical cyclone tracks during El Niño years. Additionally, weaker easterly and stronger southerly winds on the western side of the North Atlantic Basin exist during El Niño years. Although future tropical cyclone track projection is beyond the scope of this research, these results may provide insight into forecast improvement and ultimately better responses for coastal communities.

What to Do With Recurrent Prolapse After Vaginal Mesh Failure?

Study ObjectiveTo show that in selected cases laparoscopic sacrocolpopexy can be used for the treatment of recurrent pelvic organ prolapse after vaginal mesh surgery. MethodsStep-by-step examination of the technique using an educative video. Institutional review board approval was obtained. SettingThe authors describe two clinical cases of treatment of recurrent pelvic organ prolapse, after a vaginal mesh surgery, using laparoscopic sacrocolpopexy. PatientsA 56-year old patient (para 3, gravida 2) presented with the sentation of bulging in the vagina. On physical examination, the patient had a grade 2-3 vaginal apical prolapse and a stage 4 rectocele. She had a slight mesh contraction but no vaginal extrusion and no pain were reported. Eleven years before, she had a vaginal total hysterectomy for pelvic organ prolapse correction and one year before she had a vaginal prolapse repair using a synthetic mesh. A laparoscopic sacrocolpopexy with bilateral ooforectomy was performed. The second case is of a 54-year old patient (para 2, gravida 2) that presented stress urinary incontinence. On physical examination, the patient had a grade 3 uterine prolapse and grade 2 cystocele. Eleven years before she had a vaginal prolapse repair using a synthetic mesh and a miduretral sling for stress urinary incontinence. Two years before, she had the miduretal sling removed for recurrent urinary infections and dysuria. A laparoscopic sub-total hysterectomy with salpingectomy and ovarian conservation, sacrocolpopexy and a Burch colposuspension was performed. Measurements and Main ResultsThe procedures and postoperative recovery were uneventful. No minor or major complications occurred. The patients were discharged three days after surgery. ConclusionLaparoscopic sacrocolpopexy is a promising approach for the treatment of recurrent pelvic organ prolapse after vaginal mesh surgery. It appears to be feasible, safe, and effective.

Optimizing the discharge voltage in magnetron sputter deposition of high quality Al-doped ZnO thin films

The role of negative ions in the sputter deposition of oxides can be termed negative in the sense that they typically cause radiation-induced structural damage during film growth. For magnetron sputtered Al-doped ZnO (AZO) films, efforts have been made to alleviate the radiation damage by decreasing the discharge voltage |Vd|, with ∼100 V being the lower limit explored. Here, the authors report initial results of depositing highly conductive and transparent AZO films by reducing |Vd| down to 40 V. The deposition was performed by sputtering an AZO target using dense magnetron discharges, in which an 81 MHz radio frequency power was superimposed onto a DC power applied to the cathode. The authors found an optimal |Vd| window within which high quality AZO films, with a &amp;lt;4 × 10−4 Ω cm resistivity, &amp;gt;30 cm2/(V s) Hall mobility, and &amp;gt;88% visible transmittance, were obtained at relatively high deposition rates (&amp;gt;30 nm/min). Based on the corresponding structural features, i.e., a full mass density coupled with a slight c-axis contraction along the out-of-plane direction, energetic negative ions were identified to have dominated in the structural evolution. The |Vd| window was then interpreted in terms of two competitive kinetic processes simultaneously caused by the energetic negative ions: void reduction via ballistic relocation of atoms as well as residual radiation-induced damage. The findings thus reveal a positive role (i.e., concomitant densification) played by the negative ions in growing high quality fully dense AZO films, which has been overshadowed by the excessive radiation damage induced by ions with relatively higher energies.