bluuebunny/crossref_metadata_2025 huggingface dataset:
Voltage‐clamp analysis of the potassium current that produces a negative‐going action potential in Ascaris muscle.
Authors: Byerly L , Masuda M O
Published: August 2023

1. A voltage clamp has been developed for the pharyngeal muscle of the nematode Ascaris lumbricoides and has been used to analyse the potassium current that produces a negative‐going, regenerative action potential in this muscle. 2. Depolarizing voltage steps elicit a sustained inward current; returning the membrane voltage to the resting level evokes a strong, transient, outward current. This outward current reverses direction at the same voltage as that reached by the negative‐going spike and is identified as the negative spike current. 3. The negative spike current decays with a time constant of 30 msec at voltages more negative than ‐30mV. This inactivation of the negative spike conductance is removed by holding the membrane at potentials more positive than ‐15mV. The time constant for removal of inactivation decreases from more than 300 msec at ‐15 mV to about 30 msec at +10 mV. 4. When inactivation has been removed, the negative spike conductance is turned on by stepping to potentials more negative than ‐15 mV. 5. Although the reversal potential for this current depends strongly on [K+]o (42 mV/decade), the potential at which the conductance is turned on is independent of [K+]o. 6. External Na+ seems to facilitate the negative spike current. Reduction of [Na+]o reduces its conductance and shifts the reversal potential to more positive values. 7. External Rb+ and Cs+ show voltage‐dependent blocking of this current. 8. This K current is different from all the K currents which have been studied previously; however, it is analogous to the classical Na current of nerve and muscle, except for an inversion of the voltage dependencies.
Free‐flow reabsorption of glucose, sodium, osmoles and water in rat proximal convoluted tubule.
Authors: Bishop J H , Green R , Thomas S
Published: August 2023

1. Reabsorption of glucose, sodium, total solute (osmoles) and water in the rat proximal tubule (pars convoluta) were studied by free‐flow micropuncture at normal (saline‐infused), suppressed (saline with phlorizin) and elevated (glucose infusion) glucose reabsorption rates. 2. Phlorizin completely inhibited net glucose reabsorption, approximately halved reabsorption of sodium, total solutes and water, and reduced single nephron glomerular filtration rate (SNGFR). 3. In saline and glucose‐infused groups, there were no significant differences between SNGFR nor between reabsorptions (fractional and absolute) of either sodium, total solute or water, which were uniformly distributed along segments assessible to micropuncture. 4. Glucose reabsorptive capacity existed along the entire pars convoluta, with highest reabsorptive rates in convolutions closest to the glomerulus (in saline‐infused rats, 90% fractional reabsorption at 2 mm, over 95% at end pars convoluta; in glucose‐infused rats, 55 and 90%, respectively). 5. In saline and glucose infused rats, a significant correlation existed between net glucose and sodium reabsorption, but the regression slopes differed and correlations became non‐significant when the reabsorptive fluxes were factored by SNGFR. 6. For all groups, the majority of tubular fluid (TF) concentrations of osmoles and sodium were lower than those in plasma (over‐all mean TFosm)Posm = 0.973 +/‐ 0.004, P less than 0.001; TFNa /PNa = 0.964 +/‐ 0.005, P less than 0.001). 7. Correspondingly, calculated osmolal and sodium concentrations in the reabsorbate were greater than those in plasma, and were significantly correlated with distance to puncture site with maximal values in the most proximal convolutions (for osmolality, approximately +79 m‐osmole kg‐1 water at 1 mm).
The effect of bupivacaine aerosol on the activity of pulmonary stretch and 'irritant' receptors.
Authors: Fahim M , Jain S K
Published: August 2023

1. Experiments have been done on anaesthetized, paralysed and artificially ventilated cats. 2. Vagal single afferent fibres showing discharges in phase with respiration were isolated in the neck. Two types of fibres were studied at different tidal volumes: (i) showing slowly adapting discharges from the pulmonary stretch receptors; (ii) showing rapidly adapting discharges from the lung 'irritant' receptors. The effect of bupivacaine aerosol, administered by positive pressure inflations, was recorded on the pattern of fibre discharge. 3. The pulmonary stretch fibres were further classified into low‐threshold and higher‐threshold fibres according to the standard criteria. Bupivacaine aerosol blocked activity in all the low‐threshold and in the majority of the higher‐threshold fibres. 4. Of the rapidly adapting fibres, bupivacaine completely blocked activity at some tidal volumes and markedly reduced it at most others. 5. The fibre activity data are presented. It is concluded that although bupivacaine aerosol markedly reduced impulse activity in all three types of fibres, the data suggest that there is a small difference in the ease with which low‐threshold fibres on the one hand and higher‐threshold and "irritant" fibres on the other hand are affected. The reasons for this difference in the behaviour are not understood.
Prostaglandins and the sources of their production in a mild imflammatory lesion in sheep.
Authors: Greenwood B , Kerry P J
Published: August 2023

1. Wound fluid was collected from a subcutaneous lesion in the shoulder region of sheep by implanting a PTFE sampling chamber from which a catheter led to the skin surface. 2. The neutrophil granulocyte numbers and prostaglandin content of the wound fluid were studied, prostaglandins being identified by thin layer chromatography and measured by bio‐assay. The major prostaglandin component was E2. 3. There was no clear relation between the amounts of prostaglandin present and the numbers of neutrophils in the fluid. 4. A subcutaneously implanted double chamber permitted perfusion of the lesion and thereby the study of the rate of prostaglandin production and the rate of disappearance of isotopically labelled prostaglandin from the lesion. The rate of leucocyte entry into the wound fluid could also be measured. 5. When the cutaneous muscle through which the chamber had been implanted was biopsied and incubated in vitro it was found to produce prostaglandin E2 in quantities which could be correlated with the weight of the incubated muscle. 6. These results suggest that a major contributor to the prostaglandin content of the wound fluid is the cutaneous striped muscle.
Sodium transport in the hen lower intestine. induction of sodium sites in the brush border by a low sodium diet.
Authors: Bindslev N
Published: August 2023

1. The fluxes of Na were measured on isolated coprodeal mucosa at 1‐‐220 mM‐Na from hens on low (L) and high (H) Na diets with the purpose of finding the location and characteristics of Na sites activated in the cellular pathway by L. 2. The influx across the brush border, JNamc, and the transmural fluxes, JNasm and JNams, were determined. Effects on these fluxes of ouabain, 10(‐3) M in the serosal solution, and amiloride, 10(‐4) M in the mucosal solution, were studied for both dietary states. 3. JNamc was 5‐‐22 (L) and 0‐‐0.8 (H) muequiv/cm2.hr at 130 mM‐Na corrected for the paracellular flux of Na. The JNamc (H) is tenfold smaller than found by Choshniak, Munck & Skadhauge (1977). This discrepancy is at present inexplicable. Amiloride completely inhibited JNamc (L). Preincubation in 0 or 130 mM‐Na had no effect on JNamc. Ouabain reduced JNamc (L) by only about 37% after preincubation at 130 mM‐Na. The Kt of JNamc was 5.1 (L) and 50.6 (H) mM‐Na. 4. JNasm was 50 (H) and 61 (L) n‐equiv/cm2.hr at 6.5 mM‐Na. Ouabain increased JNasm by 360% in the low Na state. The increased JNasm was inhibited 74‐‐100% by amiloride. This is interpreted as a ouabain induced Na‐Na exchange at the basolateral Na‐K‐ATPase and an almost complete block of JNacm by amiloride. A similar exchange of Na at the basolateral membrane in the high‐Na state was revealed by 'opening' the brush border for Na with monensin added to the mucosal solution. Amiloride in itself prevented a 50% recirculation of Na via the paracellular route and back across the cells in the low Na state. 5. JNams was 5.6 (L) muequiv/cm2.hr and 187 (L) microA/cm2 at 6.5 mM‐Na. Amiloride reduced these values to 0.4 muequiv/cm2.hr and 5.8 microA/cm2. On addition of amiloride the transmural resistance in (L) coprodea at 130 mM‐Na increased from 140 to 190 and it remained unchanged at 260 omega cm2 in (H) coprodea. The resistance of (L) birds, 163, was not affected by ouabain, 166 (L) omega cm2. 6. 20:1 NaCl dilution potentials at the mucosal side of 17‐‐18 mV (L) and nearly zero (H) had half‐times around 1 sec. Amiloride eliminated completely these diffusion potentials. The short half‐time indicates a location in the brush border of sodium specific sites induced by the low‐Na diet. This conclusion is oppsite to that described by Choshniak et al. (1977). 7. Ion selectivity, voltage‐‐current and conductance‐‐concentration relations in the presence of amiloride indicated a weakly cation selective and highly hydrated pathway, which was also thick and with neutral sites. This fits a paracellular route with the limiting barrier for ions at the tight junction.
Mouse pancreatic beta‐cells: tetraethylammonium blockage of the potassium permeability increase induced by depolarization.
Authors: Atwater I , Ribalet B , Rojas E
Published: August 2023

1. Membrane potentials and input resistance were measured in beta‐cells from mouse pancreatic islets of Langerhans in the presence or absence of D‐glucose. 2. Tetraethylammonium (TEA) (a specific blocker of the K permeability increase induced by shifts in membrane potential from negative to positive values) was externally applied and its effects on potentials and input resistance evaluated. 3. In the absence of glucose, addition of TEA up to 20 mM to the perifusion medium did not affect the resting potential and the input resistance, the selectivity ratio PK/PNa (calculated from the constant field equation) remaining unchanged at about 30. 4. The characteristic response of the beta‐cell membrane potential, in the presence of glucose, is a fluctuation between a silent phase at about ‐50 mV and an active phase at about ‐40 mV giving rise to a train of spikes. TEA abolishes this pattern and very much reduces the graded response of spike frequency normally seen with different concentrations of glucose. 5. Addition of glucose in the presence of up to 20 mM‐TEA induces an increase in membrane resistance of about 4.10(7) omega. 6. TEA lowers the glucose level required to trigger the electrical activity from about 5.6 to about 4.6 mM. 7. TEA blocks the repolarization phase of action potentials induced by the addition of glucose or by depolarizing intracellular current injection. 8. In the presence of 11.1 mM‐glucose and 20 mM‐TEA the action potentials frequently crossed the zero line, the membrane potential reaching up to 25 mV during the peak of the spikes.
The membrane current of single rod outer segments.
Authors: Baylor D A , Lamb T D , Yau K W
Published: August 2023

1. Outer segments of individual rods in the retina of the toad, Bufo marinus, were drawn into a glass pipette to record the membrane current. 2. Light flashes evoked transient outward currents. The peak response amplitude was related to flash intensity by a Michaelis equation with half‐saturating intensity about 1 photon mum‐2. 3. The saturating response amplitude ranged up to 27 pA and corresponded closely to complete suppression of the steady inward current present in darkness. 4. For a given cell the saturating response amplitude varied linearly with the length of outer segment within the pipette. This is consistent with a uniform density of light‐sensitive channels and negligible gradient of membrane potential along the outer segment. 5. Responses to bright flashes never showed the relaxation from an initial peak seen previously in intracellular voltage recordings, suggesting that the conductance change responsible for the relaxation does not occur in the outer segment. 6. Responses to local illumination of only the recorded outer segment were very similar to those obtained with diffuse light at the same intensity, indicating that peripheral rods made little contribution to the responses. 7. The spectral sensitivity of 'red' rods was consistent with a retinal1‐based pigment with lambda max = 498 +/‐ 2 nm. 8. The kinetics of the response were consistent with four stages of delay affecting action of the internal transmitter. Responses were faster at the basal end of the outer segment than at the distal tip. 9. Background light reduced the sensitivity to a superposed dim test flash and shortened the time course of the response, indicating that adapting light modifies the kinetics and gain of the transduction mechanism within the outer segment. 10. Responses to dim lights exhibited pronounced fluctuations which are attributed in the succeeding paper (Baylor, Lamb & Yau, 1979) to the quantal nature of light.
Methods for the Automated Determination of Sustained Maximum Amplitudes in Oscillating Signals
Authors: DeVol Nathaniel , Saldaña Christopher , Fu Katherine
Published: August 2023

Machine condition monitoring has been proven to reduce machine downtime and increase productivity. The state-of-the-art research uses vibration monitoring for tasks such as maintenance and tool wear prediction. A less explored aspect is how vibration monitoring might be used to monitor equipment sensitive to vibration. In a manufacturing environment, one example of where this might be needed is in monitoring the vibration of optical linear encoders used in high-precision machine tools and coordinate measuring machines. Monitoring the vibration of sensitive equipment presents a unique case for vibration monitoring because an accurate calculation of the maximum sustained vibration is needed, as opposed to extracting trends from the data. To do this, techniques for determining sustained peaks in vibration signals are needed. This work fills this gap by formalizing and testing methods for determining sustained vibration amplitudes. The methods are tested on simulated signals based on experimental data. Results show that processing the signal directly with the novel Expire Timer method produces the smallest amounts of error on average under various test conditions. Additionally, this method can operate in real-time on streaming vibration data.
Improving Uniformity of Cell Distribution in Post-Inkjet-Based Bioprinting
Authors: Liu Jiachen , Xu Changxue
Published: August 2023

Advancements in additive manufacturing enable the fabrication of in vitro biomimetic grafts leveraging biological materials and cells for various biomedical applications. The realization of such biofabrication typically requires time from minutes to hours depending on the scale and complexity of the models. During direct biofabrication, cell sedimentation with the resultant aggregation is extensively deemed to be one of the acute problems for precise and reliable inkjet-based bioprinting. It often results in highly unstable droplet formation, nozzle clogging, and non-uniformity of post-printing cell distribution. Our previous study has implemented active bioink circulation to mitigate cell sedimentation and aggregation within the bioink reservoir. This study focuses on the comparison of post-printing cell distribution within formed microspheres and one-layer sheets with and without active circulation. The experimental results have demonstrated a significant improvement in post-printing cell distribution under implemented active circulation. Moreover, the printed sheet samples are subject to three-day incubation to investigate the effect of cell distribution on cell viability and proliferation. It shows that compared to non-uniform cell distribution, the uniform cell distribution significantly improves cell viability (92% versus 77% at Day 3) and cell proliferation (3.3 times versus 1.7 times at Day 3). The preliminary results in this paper have demonstrated not only the high effectiveness of the active bioink circulation to improve post-printing cell distribution within microspheres and one-layer sheets, but also the critical role of the uniform post-printing cell distribution in promoting cell viability and proliferation.
Effect of temperature on the acoustic response and stability of size-isolated protein-shelled ultrasound contrast agents and SonoVue
Authors: Kaushik Anuj , Khan Aaqib H. , Pratibha  , Dalvi Sameer V. , Shekhar Himanshu
Published: August 2023

Limited work has been reported on the acoustic and physical characterization of protein-shelled UCAs. This study characterized bovine serum albumin (BSA)-shelled microbubbles filled with perfluorobutane gas, along with SonoVue, a clinically approved contrast agent. Broadband attenuation spectroscopy was performed at room (23 ± 0.5 °C) and physiological (37 ± 0.5 °C) temperatures over the period of 20 min for these agents. Three size distributions of BSA-shelled microbubbles, with mean sizes of 1.86 μm (BSA1), 3.54 μm (BSA2), and 4.24 μm (BSA3) used. Viscous and elastic coefficients for the microbubble shell were assessed by fitting de Jong model to the measured attenuation spectra. Stable cavitation thresholds (SCT) and inertial cavitation thresholds (ICT) were assessed at room and physiological temperatures. At 37 °C, a shift in resonance frequency was observed, and the attenuation coefficient was increased relative to the measurement at room temperature. At physiological temperature, SCT and ICT were lower than the room temperature measurement. The ICT was observed to be higher than SCT at both temperatures. These results enhance our understanding of temperature-dependent properties of protein-shelled UCAs. These findings study may guide the rational design of protein-shelled microbubbles and help choose suitable acoustic parameters for applications in imaging and therapy.
Reliability of spectral-temporal ripple tests in children
Authors: Kirby Benjamin J. , Sullivan Morgan A.
Published: August 2023

Spectral-temporal ripple tests in both adaptive and non-adaptive versions have been proposed for use in the audiology clinic. Though these methods have been found to yield repeatable results and to be correlated with each other in adults, similar information about test performance in children is lacking. In this preliminary study, children ages 6–12 years completed two repetitions of the adaptive spectral-temporally modulated ripple test (SMRT) and non-adaptive SMRT Lite for computeRless Measurement (SLRM) test. The first and second repetitions of the SLRM were correlated. Though mean performance on the SMRT was significantly correlated with the SLRM, the first and second repetitions of the SMRT were not significantly correlated.
Unraveling allostery within the angiotensin II type 1 receptor for Gα
q
and β-arrestin coupling
Authors: Cao Yubo , van der Velden Wijnand J. C. , Namkung Yoon , Nivedha Anita K. , Cho Aaron , Sedki Dana , Holleran Brian , Lee Nicholas , Leduc Richard , Muk Sanychen , Le Keith , Bhattacharya Supriyo , Vaidehi Nagarajan , Laporte Stéphane A.
Published: August 2023

G protein–coupled receptors engage both G proteins and β-arrestins, and their coupling can be biased by ligands and mutations. Here, to resolve structural elements and mechanisms underlying effector coupling to the angiotensin II (AngII) type 1 receptor (AT1R), we combined alanine scanning mutagenesis of the entire sequence of the receptor with pharmacological profiling of Gα
q
and β-arrestin engagement to mutant receptors and molecular dynamics simulations. We showed that Gα
q
coupling to AT1R involved a large number of residues spread across the receptor, whereas fewer structural regions of the receptor contributed to β-arrestin coupling regulation. Residue stretches in transmembrane domain 4 conferred β-arrestin bias and represented an important structural element in AT1R for functional selectivity. Furthermore, we identified allosteric small-molecule binding sites that were enclosed by communities of residues that produced biased signaling when mutated. Last, we showed that allosteric communication within AT1R emanating from the Gα
q
coupling site spread beyond the orthosteric AngII-binding site and across different regions of the receptor, including currently unresolved structural regions. Our findings reveal structural elements and mechanisms within AT1R that bias Gα
q
and β-arrestin coupling and that could be harnessed to design biased receptors for research purposes and to develop allosteric modulators.
Mitochondrial fission fueled by fasting
Authors: Wong Wei
Published: August 2023

Fasting activates mTORC2 to stimulate mitochondrial fission and support mitochondrial respiration.
Mechanisms of nucleic acid degradation and high hydrostatic pressure tolerance of a novel deep-sea wall-less bacterium
Authors: Zheng Rikuan , Wang Chong , Cai Ruining , Shan Yeqi , Sun Chaomin
Published: August 2023

Wall-less bacteria are broadly distributed in diverse habitats. They evolved from a common ancestor within the
Firmicutes
phylum through reductive evolution. Here, we report the cultivation, characterization, and polyphasic taxonomic analysis of the novel free-living wall-less bacterium,
Hujiaoplasma nucleasis
zrk29. We demonstrated that strain zrk29 had a strong ability to degrade DNA and RNA both under laboratory conditions and in the deep sea. We found that nucleic acids induced strain zrk29 to release chronic bacteriophages which supported strain zrk29 and other marine bacteria to metabolize nucleic acids without lysing host cells. We also showed that strain zrk29 tolerated high hydrostatic pressure via two pathways: (i) by transporting cations into its cells to increase intracellular osmotic pressure and (ii) by adjusting the unsaturated fatty acid chain content in its cell membrane phospholipids to increase cell membrane fluidity. This study extends our understanding of free-living wall-less bacteria and provides a useful model to explore the unique adaptation mechanisms of deep-sea microbes.

IMPORTANCE

The unique physiology and survival strategies of the
Tenericutes
bacterium—a typical wall-less bacterium—have fascinated scientists and the public, especially in extreme deep-sea environments where there is high hydrostatic pressure (HHP) and limited availability of nutrients. Here, we have isolated a novel free-living
Tenericutes
strain from deep-sea sediment and have found that it metabolizes nucleic acids with the support of chronic bacteriophages. This
Tenericutes
strain tolerates HHP stress by increasing intracellular osmotic pressure and the unsaturated fatty acid chain content of phospholipids in its cell membrane. Our results provide insights into the unique physiology of deep-sea free-living
Tenericutes
bacteria and highlight the significant role that chronic bacteriophages play in assisting wall-less bacteria to adapt to harsh conditions.
Interaction of DNA Methyltransferase Dnmt3a with Phosphorus Analogs of S-Adenosylmethionine and S-Adenosylhomocysteine
Authors: Filonov V. L. , Khomutov M. A. , Sergeev A. V. , Khandazhinskaya A. L. , Kochetkov S. N. , Gromova E. S. , Khomutov A. R.
Published: August 2023

Enzymatic methyltransferase reactions are of crucial importance for cell metabolism. S-Adenosyl-L-methionine (AdoMet) is a main donor of the methyl group. DNA, RNA, proteins, and low-molecular-weight compounds are substrates of methyltransferases. In mammals, DNA methyltransferase Dnmt3a de novo methylates the C5 position of cytosine residues in CpG sequences in DNA. The methylation pattern is one of the factors that determine the epigenetic regulation of gene expression. Here, interactions with the catalytic domain of Dnmt3a was for the first time studied for phosphonous and phosphonic analogs of AdoMet and S-adenosyl-L-homocysteine (AdoHcy), in which the carboxyl group was substituted for respective phosphorus-containing group. These AdoMet analogs were shown to be substrates of Dnmt3a, and the methylation efficiency was only halved as compared with that of natural AdoMet. Both phosphorus-containing analogs of AdoHcy, which is a natural methyltransferase inhibitor, showed similar inhibitory activities toward Dnmt3a and were approximately four times less active than AdoHcy. The finding that the phosphonous and phosphonic analogs are similar in activity was quite unexpected because the geometry and charge of their phosphorus-containing groups differ substantially. The phosphorus-containing analogs of AdoMet and AdoHcy are discussed as promising tools for investigation of methyltransferases.
Ultrasound assessment of endotracheal tube depth in neonates: a prospective feasibility study
Authors: Levkovitz Orly , Schujovitzky Dana , Stackievicz Rodica , Fayoux Pierre , Morag Iris , Litmanovitz Ita , Arnon Shmuel , Bauer Sofia
Published: August 2023

Objective

To examine the reliability of a novel ultrasound (US) method for assessment of endotracheal tube (ETT) position in neonates.

Design

Prospective, observational, single-centre, feasibility study.

Setting

Level III neonatal intensive care unit.

Patients

Term and preterm neonates requiring endotracheal intubation.

Intervention

US measurement of the ETT tip to right pulmonary artery (RPA) distance was used to determine ETT position according to one-fourth to three-fourths estimated tracheal length for weight. US demonstration of pleural sliding and diaphragmatic movement was also assessed. Chest radiography (CXR) was performed following each intubation.

Main outcome measures

Agreement between US assessment of ETT tip position and CXR served as the gold standard. Sensitivity, specificity, positive and negative predictive values for each US method and correlation between ETT tip to RPA distance on US, and ETT tip to carina distance on CXR were assessed.

Results

Forty-two US studies were performed on 33 intubated neonates. US evaluation of ETT-RPA distance identified 100% of ETTs positioned correctly: 77% deep and 80% high, demonstrating strong agreement with CXR (kappa=0.822). Sensitivity was 78%, specificity 100%, positive predictive value 100% and negative predictive value 86%. US ETT-RPA distance strongly correlated with CXR ETT-carina distance (r=0.826). No significant agreement was found between CXR and US assessment of pleural sliding and diaphragmatic movement. No adverse events were encountered during US scans.

Conclusion

US evaluation of ETT-RPA distance demonstrated excellent accuracy for determining ETT position in neonates compared with CXR. More research is needed to support its feasibility in clinical settings.
Management of perimenopausal and menopausal symptoms
Authors: Duralde Erin R , Sobel Talia H , Manson JoAnn E
Published: August 2023

Most women worldwide experience menopausal symptoms during the menopause transition or postmenopause. Vasomotor symptoms are most pronounced during the first four to seven years but can persist for more than a decade, and genitourinary symptoms tend to be progressive. Although the hallmark symptoms are hot flashes, night sweats, disrupted sleep, and genitourinary discomfort, other common symptoms and conditions are mood fluctuations, cognitive changes, low sexual desire, bone loss, increase in abdominal fat, and adverse changes in metabolic health. These symptoms and signs can occur in any combination or sequence, and the link to menopause may even be elusive. Estrogen based hormonal therapies are the most effective treatments for many of the symptoms and, in the absence of contraindications to treatment, have a generally favorable benefit:risk ratio for women below age 60 and within 10 years of the onset of menopause. Non-hormonal treatment options are also available. Although a symptom driven treatment approach with individualized decision making can improve health and quality of life for midlife women, menopausal symptoms remain substantially undertreated by healthcare providers.
Stakeholder’s perspectives of postnatal discharge: a qualitative evidence synthesis
Authors: Harvey Chloe Mercedes , Smith Helen , Portela Anayda , Movsisyan Ani
Published: August 2023

Introduction

Discharge preparation prior to leaving a health facility after childbirth offers a critical window of opportunity for women, parents and newborns to receive support for the transition to care at home. However, research suggests that the quality of discharge preparation following childbirth is variable. This review synthesises qualitative evidence on stakeholder perspectives of postnatal discharge.

Methods

We conducted a thematic synthesis of qualitative studies included in a larger published scoping review on discharge preparedness and readiness (reported in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews). For inclusion, in the qualitative evidence synthesis, studies had to have used qualitative methods for data collection and analysis to capture the perspectives of women, parents and health workers. Key characteristics and findings were extracted, and thematic analysis was used to inductively develop a conceptual coding framework.

Results

Of a total of 130 research documents (published research articles and grey literature), six studies met the inclusion criteria; five were conducted in high-income countries, five were published in English and one was published in Swedish. Studies reported on the experiences of women, fathers and midwives with the number of participants ranging from 12 to 324. Nine descriptive themes (findings) were identified. From these, three high-level analytical themes were generated: (1) health workers need support to optimise the postnatal discharge process; (2) the allocated time for, and timing of, discharge is rushed; (3) overlooking women’s and fathers’/partners’ needs leads to feelings of exclusion.

Conclusions

Findings suggest an overall feeling of dissatisfaction among women, parents and midwives with the current provision of discharge preparation. In particular, women and midwives expressed frustration at the lack of time and resources available for ensuring adequate quality of care prior to discharge. The perspectives of included stakeholders indicate a demand for increased focus on the emotional and social needs of women and families during discharge preparation as well as better engagement of fathers and other family members. The qualitative evidence available indicates the likely positive impact of adequate discharge preparation if the identified service and system barriers can be overcome. As the updated WHO recommendations on postnatal care become embedded in country health systems and policies, there may be renewed interest on values, preferences and perspectives at system, service and end-user level.
Associations between air pollution and mental health service use in dementia: a retrospective cohort study
Authors: Ronaldson Amy , Stewart Robert , Mueller Christoph , Das-Munshi Jayati , Newbury Joanne B , Mudway Ian S , Broadbent Matthew , Fisher Helen L , Beevers Sean , Dajnak David , Hotopf Matthew , Hatch Stephani L , Bakolis Ioannis
Published: August 2023

Background

Little is known about the role of air pollution in how people with dementia use mental health services.

Objective

We examined longitudinal associations between air pollution exposure and mental health service use in people with dementia.

Methods

In 5024 people aged 65 years or older with dementia in South London, high resolution estimates of nitrogen dioxide (NO2) and particulate matter (PM2.5and PM10) levels in ambient air were linked to residential addresses. Associations between air pollution and Community Mental Health Team (CMHT) events (recorded over 9 years) were examined using negative binomial regression models. Cognitive function was measured using the Mini Mental State Examination (MMSE) and health and social functioning was measured using the Health of the Nation Outcomes Scale (HoNOS65+). Associations between air pollution and both MMSE and HoNOS65+ scores were assessed using linear regression models.

Findings

In the first year of follow-up, increased exposure to all air pollutants was associated with an increase in the use of CMHTs in a dose-response manner. These associations were strongest when we compared the highest air pollution quartile (quartile 4: Q4) with the lowest quartile (Q1) (eg, NO2: adjusted incidence rate ratio (aIRR) 1.27, 95% CI 1.11 to 1.45, p<0.001). Dose-response patterns between PM2.5and CMHT events remained at 5 and 9 years. Associations were strongest for patients with vascular dementia. NO2levels were linked with poor functional status, but not cognitive function.

Conclusions

Residential air pollution exposure is associated with increased CMHT usage among people with dementia.

Clinical implications

Efforts to reduce pollutant exposures in urban settings might reduce the use of mental health services in people with dementia, freeing up resources in already considerably stretched psychiatric services.
In vivo polarisation sensitive optical coherence tomography for fibrosis assessment in interstitial lung disease: a prospective, exploratory, observational study
Authors: Vaselli Margherita , Kalverda-Mooij Kirsten , Thunnissen Erik , Tanck Michael W T , Mets Onno M , van den Berk Inge A H , Annema Jouke T , Bonta Peter I , de Boer Johannes F
Published: August 2023

Introduction

Endobronchial polarisation sensitive optical coherence tomography (EB-PS-OCT) is a bronchoscopic imaging technique exceeding resolution of high-resolution CT (HRCT) by 50-fold. It detects collagen birefringence, enabling identification and quantification of fibrosis.

Study aim

To assess pulmonary fibrosis in interstitial lung diseases (ILD) patients with in vivo EB-PS-OCT using histology as reference standard.

Primary objective

Visualisation and quantification of pulmonary fibrosis by EB-PS-OCT.

Secondary objectives

Comparison of EB-PS-OCT and HRCT detected fibrosis with histology, identification of ILD histological features in EB-PS-OCT images and comparison of ex vivo PS-OCT results with histology.

Methods

Observational prospective exploratory study. Patients with ILD scheduled for transbronchial cryobiopsy or surgical lung biopsy underwent in vivo EB-PS-OCT imaging prior to tissue acquisition. Asthma patients were included as non-fibrotic controls. Per imaged lung segment, fibrosis was automatically quantified assessing the birefringent area in EB-PS-OCT images. Fibrotic extent in corresponding HRCT areas and biopsies were compared with EB-PS-OCT detected fibrosis. Microscopic ILD features were identified on EB-PS-OCT images and matched with biopsies from the same segment.

Results

19 patients were included (16 ILD; 3 asthma). In 49 in vivo imaged airway segments the parenchymal birefringent area was successfully quantified and ranged from 2.54% (no to minimal fibrosis) to 21.01% (extensive fibrosis). Increased EB-PS-OCT detected birefringent area corresponded to increased histologically confirmed fibrosis, with better predictive value than HRCT. Microscopic ILD features were identified on both in vivo and ex vivo PS-OCT images.

Conclusions

EB-PS-OCT enables pulmonary fibrosis quantification, thereby has potential to serve as an add-on bronchoscopic imaging technique to diagnose and detect (early) fibrosis in ILD.
Red blood cell capacity of modern menstrual products: considerations for assessing heavy menstrual bleeding
Authors: DeLoughery Emma , Colwill Alyssa C , Edelman Alison , Samuelson Bannow Bethany
Published: August 2023

Background

Heavy menstrual bleeding affects up to one third of menstruating individuals and has a negative impact on quality of life. The diagnosis of heavy menstrual bleeding is based primarily on history taking, which is highly dependent on traditional disposable menstrual products such as pads and tampons. Only tampons undergo industry-regulated testing for absorption capacity. As use of alternative menstrual products is increasing, there is a need to understand how the capacity of these products compare to that of standard products.

Methods

A variety of commercially available menstrual products (tampons, pads, menstrual cups and discs, and period underwear) were tested in the laboratory to determine their maximal capacity to absorb or fill using expired human packed red blood cells. The volume of blood necessary for saturation or filling of the product was recorded.

Results

Of the 21 individual menstrual hygiene products tested, a menstrual disc (Ziggy, Jiangsu, China) held the most blood of any product (80 mL). The perineal ice-activated cold pack and period underwear held the least (<3 mL each). Of the product categories tested, on average, menstrual discs had the greatest capacity (61 mL) and period underwear held the least (2 mL). Tampons, pads (heavy/ultra), and menstrual cups held similar amounts of blood (approximately 20–50 mL).

Conclusion

This study found considerable variability in red blood cell volume capacity of menstrual products. This emphasises the importance of asking individuals about the type of menstrual products they use and how they use them. Further understanding of capacity of newer menstrual products can help clinicians better quantify menstrual blood loss, identify individuals who may benefit from additional evaluation, and monitor treatment.
On Ageing and Maturing
Authors: Simkulet William
Published: August 2023

Räsänen draws a distinction between chronological age and biological age and argues that biological ageing is (sometimes) desirable. To demonstrate this, he asks us to consider the case of April, who like Karel Čapek’s Elina Makropulos, has stopped biologically ageing. Unlike Makropulos, though, April’s biological ageing was halted before puberty, so she will never mature into adulthood. Räsänen contends this case shows ageing can be desirable, but this equivocates between maturing and ageing. Here I argue biological ageing, or the wear and tear normally associated with chronological ageing, isprima facieundesirable, but that maturing can beprima faciedesirable.
Reducing e-cigarette use among youth and young adults: evidence of the truth campaign’s impact
Authors: Hair Elizabeth C , Kreslake Jennifer M , Tulsiani Shreya , McKay Tatum , Vallone Donna
Published: August 2023

Background

Mass media campaigns have been shown to be effective in reducing cigarette use. However, evidence is limited for whether campaigns can shift e-cigarette use among youth and young adults (YYA). To assess the impact of the truth anti-e-cigarette campaign, which focused on the effects of vaping on mental health, this study examines the relationship between campaign awareness and e-cigarette behaviour among YYA.

Methods

Data from weekly cross-sectional surveys of YYA aged 15–24 years from September 2021 to October 2022 were used for multilevel models assessing how weekly campaign awareness is related to intentions to use e-cigarettes and current e-cigarette use (past 30 days). Weekly campaign awareness was calculated by averaging individual-level awareness for each week. Control variables included individual-level campaign awareness, sociodemographics, perceived financial situation, parental smoking, sensation seeking, and mental health.

Results

Weekly campaign awareness ranged from 50% to 78%, with most weeks (77%) being within 65% and 75% of weekly campaign awareness. At weekly awareness levels between 65% and 75%, there was a significant association with lower intentions to use e-cigarettes. A dose–response relationship was observed for current use: compared with weeks with lower (<65%) awareness, weeks with awareness of 65–70% had 14% lower odds of current use, weeks with 70–75% awareness had 16% lower odds and weeks with >75% weekly awareness had 18% lower odds (p=0.018, p=0.009 and p=0.007, respectively).

Conclusions

Findings from this analysis of weekly campaign awareness demonstrate that exposure to the truth anti-e-cigarette campaign is associated with significantly lower odds of intentions to use and current use of e-cigarette among YYA.
Variation of the water-use efficiency and nutrients of Pinus armandii under different ages and growth season
Authors: Liu Yuanxi , Wu Junwen , Wu Danzi , Xiao Jiandong , Sun Jianli , Zhao Zhijuan
Published: August 2023

Seasonal changes in carbon (C), nitrogen (N), and phosphorus (P) stoichiometry and water-use efficiency (WUE) in the needles of Pinus armandii were investigated. The needles of P. armandii were sampled in January, May, August, and November 2021. The results showed that (1) the needle δ13C values of young P. armandii forests were higher than those of middle-aged P. armandii forests, and these differences were significant in winter. (2) Both young and middle-aged P. armandii forests were restricted by N and P, and P. armandii was more restricted by N in summer, autumn, and winter. (3) Needle δ13C values were significantly positively correlated with P and negatively correlated with N, C/P, and N/P in young P. armandii forests; P. armandii (especially young stands) can compensate for decreases in N-use efficiency by increasing WUE. The C, N, and P content and their stoichiometric ratios were affected by a combination of season, stand age, and WUE. This study contributes to an in-depth understanding of the adaptive mechanisms of nutrients and WUE in P. armandii in the subtropical region. Our findings also have implications for the management of P. armandii plantations in the study area.
Cost Allocation and Strategyproof Mechanism for Cover-set Games
Authors: Zhang Hao , Yu Huahui , Wang Limin , Guo Sainan
Published: August 2023

In this paper, we discuss several cost-sharing methods for cover-set games, for example, approximately budget-balanced, in the core, and/or strategyproof. Different from the traditional set cover game, in cover-set game, the elements stand for services, and each agent is both a service provider and receiver. In this study, for unselfish agents, we design a cost allocation method that can recover no less than [Formula: see text] fraction of the total cost, where [Formula: see text] and [Formula: see text] is the maximum number of receiving services among all agents. In addition, for agents who are selfish service providers with privately known valuations, we present a strategyproof charging mechanism, further, the total cost is no more than [Formula: see text] times that of an optimal solution.
SELF-DIFFUSIVE SPATIOTEMPORAL PATTERNS IN A FOOD CHAIN MODEL THROUGH WEAKLY NONLINEAR ANALYSIS
Authors: SHIVAM  , SINGH TEEKAM , KUMAR MUKESH , HSIEH SUN-YUAN , SINGH KAMRED UDHAM
Published: August 2023

Density distributions of populations with self-diffusion and interaction in a spatial domain are dynamically visualized with coupled nonlinear reaction–diffusion equations. Incorporating self-diffusion terms creates a more pragmatic modeling paradigm and provides meaningful descriptions of influences on spatiotemporal pattern formation phenomena. This paper examines the effect of self-diffusion in a food chain system with a Holling type-IV functional response and the type of spatial structures forms on a geographical scale due to the random movement of species. We discussed the existence and uniqueness of a positive equilibrium solution and obtained the Turing instability conditions for the self-diffusive food chain model. Moreover, weakly nonlinear analysis close to the Turing bifurcation boundary is used to derive the amplitude equations. The stability of the amplitude equations and sufficient conditions for the emanation of spatiotemporal patterns (such as spots, stripes, and blended patterns) are investigated. The analytical results are verified with numerical simulations. The results are applicable to all environments and can be used to understand the effects of self-diffusion in other food chain models both qualitatively and quantitatively.
A FRACTAL MODEL FOR ELECTRICAL CONDUCTIVITY OF POROUS MEDIA EMBEDDED WITH A DAMAGED TREE-LIKE NETWORK
Authors: WANG PEILONG , XIAO BOQI , ZHANG YIDAN , ZHU HUAIZHI , ZHANG GUOYING , LONG GONGBO , WANG YANBIN
Published: August 2023

Predicting the electrical conductivity of porous media is important for oil reservoirs, rock physics, and fuel cells. In this work, a cuboid embedded with a damaged tree-like network is employed to denote a portion of porous media. Analytical expressions for the electrical conductivity are then derived with the fractal theory. Various structural parameters have been examined in detail for the influence of electrical conductivity. It is found that the increased number of damaged channels means more difficult ion migration and lower electrical conductivity of porous media. In addition, a decreasing length ratio or an increasing diameter ratio will increase electrical conductivity. Moreover, both the channel distribution fractal dimension and tortuosity fractal dimension result in a decrease in electrical conductivity. A comparison of the results predicted by other models yields a good agreement, validating our proposed model. These results may further interpret the transport properties of porous media.
THE CENTERED HAUSDORFF MEASURE OF THE SIERPIŃSKI GASKET
Authors: LLORENTE MARTA , MERA MARÍA EUGENIA , MORÁN MANUEL
Published: August 2023

We show that the centered Hausdorff measure, [Formula: see text] with [Formula: see text] of the Sierpiński gasket [Formula: see text], is [Formula: see text]-computable (continuous-computable), in the sense that its value is the solution of the minimization problem of a continuous function on a compact domain. We also show that [Formula: see text] is [Formula: see text]-computable (algorithmic-computable) in the sense that there is an algorithm that converges to [Formula: see text] with explicit error bounds. Using this algorithm we show that [Formula: see text].
GENERALIZATION OF ELECTRICAL RESISTANCE SCALING TO DIRAC FIELDS ON PERFORATED FRACTALS
Authors: SCHONFELD JONATHAN F.
Published: August 2023

I construct perforated, “take-away” fractals that support short-distance power-law scaling with complex exponents for Dirac (spin-1/2) propagators. The construction relies on a fortuitous ansatz for Dirac boundary conditions at the surfaces of spherical voids in a three-dimensional embedding space, and requires that boundary conditions vary from void to void and are distributed statistically. The appropriate distribution can ensure that nonzero charges (but not dipoles, which drive nontrivial power-law scaling) induced in voids cancel out in spatial averaging.