A Doctor in the House, An Ethical Consideration on Treating Their Family Members: A Mixed-Method Study.

BACKGROUND:  The ethical dilemma of doctors treating their own family members has long been a contentious issue in the field of medicine. Despite these dilemmas, doctors may feel compelled to become involved in the care of family members and reluctant to set standards for themselves. Therefore, this study aimed to assess the experience of doctors in the treatment of their families in Perambalur District, Tamil Nadu, India. METHODOLOGY:  A mixed-method study was conducted among the doctors in Perambalur District, Tamil Nadu, India from December 2021 to October 2022. A semi-structured questionnaire was used to assess the socio-demographic details and the experience of doctors in treating their family members, followed by a focused group discussion (FGD). Data were analyzed using SPSS version 16 (SPSS Inc., Chicago). A scatter plot was created to visualize the relationship between age, experience of doctors, and confidence level with the frequency of treating family members. A chi-square test was performed to find any associations, and a p-value <0.05 was considered significant. For qualitative data, a fish herringbone model was constructed. RESULTS:  A total of 72 doctors participated in the study. The study found that almost all the doctors (100%) received medical requests from family members, the median number of requests received in a year was 6.5 with an interquartile range of 4-8 and three-quarters (66.6%) of them accepted the requests and treated them. However, concerns about maintaining objectivity, emotional attachment, and loss of confidentiality were cited as primary reasons for not accepting all requests. The study also found a positive relationship between age, years of experience, and the frequency of treating family members. The FGD highlighted challenges related to potential risks in managing complex cases, emotional involvement impacting decision-making, conflicts of interest, and pressures from family members and societal norms. CONCLUSION:  In the present study, almost all the doctors received requests from their family members in the last year, and more than three-fourths of the doctors treated their family members. One-fourth of the doctors rejected requests from family members due to concerns about the potential loss of objectivity and the risk of misdiagnosing symptoms caused by emotional attachments. This study sheds light on the complexities and ethical considerations doctors face when treating family members. It emphasizes the need for medical ethics education in the curriculum to guide future doctors in making ethical decisions in such situations. Implementing clear-cut medical ethics guidelines in India would be instrumental in addressing these issues and ensuring ethical practices in the medical field.

Flow Rectification in Loopy Network Models of Bird Lungs.

We demonstrate flow rectification, valveless pumping, or alternating to direct current (AC-to-DC) conversion in macroscale fluidic networks with loops. Inspired by the unique anatomy of bird lungs and the phenomenon of directed airflow throughout the respiration cycle, we hypothesize, test, and validate that multiloop networks exhibit persistent circulation or DC flows when subject to oscillatory or AC forcing at high Reynolds numbers. Experiments reveal that disproportionately stronger circulation is generated for higher frequencies and amplitudes of the imposed oscillations, and this nonlinear response is corroborated by numerical simulations. Visualizations show that flow separation and vortex shedding at network junctions serve the valving function of directing current with appropriate timing in the oscillation cycle. These findings suggest strategies for controlling inertial flows through network topology and junction connectivity.

Hydrodynamic quantum analogs.

The walking droplet system discovered by Yves Couder and Emmanuel Fort presents an example of a vibrating particle self-propelling through a resonant interaction with its own wave field. It provides a means of visualizing a particle as an excitation of a field, a common notion in quantum field theory. Moreover, it represents the first macroscopic realization of a form of dynamics proposed for quantum particles by Louis de Broglie in the 1920s. The fact that this hydrodynamic pilot-wave system exhibits many features typically associated with the microscopic, quantum realm raises a number of intriguing questions. At a minimum, it extends the range of classical systems to include quantum-like statistics in a number of settings. A more optimistic stance is that it suggests the manner in which quantum mechanics might be completed through a theoretical description of particle trajectories. We here review the experimental studies of the walker system, and the hierarchy of theoretical models developed to rationalize its behavior. Particular attention is given to enumerating the dynamical mechanisms responsible for the emergence of robust, structured statistical behavior. Another focus is demonstrating how the temporal nonlocality of the droplet dynamics, as results from the persistence of its pilot wave field, may give rise to behavior that appears to be spatially nonlocal. Finally, we describe recent explorations of a generalized theoretical framework that provides a mathematical bridge between the hydrodynamic pilot-wave system and various realist models of quantum dynamics.

Hydrodynamic spin states.

We present the results of a theoretical investigation of hydrodynamic spin states, wherein a droplet walking on a vertically vibrating fluid bath executes orbital motion despite the absence of an applied external field. In this regime, the walker's self-generated wave force is sufficiently strong to confine the walker to a circular orbit. We use an integro-differential trajectory equation for the droplet's horizontal motion to specify the parameter regimes for which the innermost spin state can be stabilized. Stable spin states are shown to exhibit an analog of the Zeeman effect from quantum mechanics when they are placed in a rotating frame.

Equilibrium Shapes and Their Stability for Liquid Films in Fast Flows.

We study how a suspended liquid film is deformed by an external flow en route to forming a bubble through experiments and a model. We identify a family of nonminimal but stable equilibrium shapes for flow speeds up to a critical value beyond which the film inflates unstably, and the model accounts for the observed nonlinear deformations and forces. A saddle-node or fold bifurcation in the solution diagram suggests that bubble formation at high speeds results from the loss of equilibrium and at low speeds from the loss of stability for overly inflated shapes.

The onset of chaos in orbital pilot-wave dynamics.

We present the results of a numerical investigation of the emergence of chaos in the orbital dynamics of droplets walking on a vertically vibrating fluid bath and acted upon by one of the three different external forces, specifically, Coriolis, Coulomb, or linear spring forces. As the vibrational forcing of the bath is increased progressively, circular orbits destabilize into wobbling orbits and eventually chaotic trajectories. We demonstrate that the route to chaos depends on the form of the external force. When acted upon by Coriolis or Coulomb forces, the droplet's orbital motion becomes chaotic through a period-doubling cascade. In the presence of a central harmonic potential, the transition to chaos follows a path reminiscent of the Ruelle-Takens-Newhouse scenario.

Generalized Swift-Hohenberg models for dense active suspensions.

In describing the physics of living organisms, a mathematical theory that captures the generic ordering principles of intracellular and multicellular dynamics is essential for distinguishing between universal and system-specific features. Here, we compare two recently proposed nonlinear high-order continuum models for active polar and nematic suspensions, which aim to describe collective migration in dense cell assemblies and the ordering processes in ATP-driven microtubule-kinesin networks, respectively. We discuss the phase diagrams of the two models and relate their predictions to recent experiments. The satisfactory agreement with existing experimental data lends support to the hypothesis that non-equilibrium pattern formation phenomena in a wide range of active systems can be described within the same class of higher-order partial differential equations.

Mycolactone-mediated neurite degeneration and functional effects in cultured human and rat DRG neurons: Mechanisms underlying hypoalgesia in Buruli ulcer.

BACKGROUND: Mycolactone is a polyketide toxin secreted by the mycobacterium Mycobacterium ulcerans, responsible for the extensive hypoalgesic skin lesions characteristic of patients with Buruli ulcer. A recent pre-clinical study proposed that mycolactone may produce analgesia via activation of the angiotensin II type 2 receptor (AT2R). In contrast, AT2R antagonist EMA401 has shown analgesic efficacy in animal models and clinical trials for neuropathic pain. We therefore investigated the morphological and functional effects of mycolactone in cultured human and rat dorsal root ganglia (DRG) neurons and the role of AT2R using EMA401. Primary sensory neurons were prepared from avulsed cervical human DRG and rat DRG; 24 h after plating, neurons were incubated for 24 to 96 h with synthetic mycolactone A/B, followed by immunostaining with antibodies to PGP9.5, Gap43, ß tubulin, or Mitotracker dye staining. Acute functional effects were examined by measuring capsaicin responses with calcium imaging in DRG neuronal cultures treated with mycolactone. RESULTS: Morphological effects: Mycolactone-treated cultures showed dramatically reduced numbers of surviving neurons and non-neuronal cells, reduced Gap43 and ß tubulin expression, degenerating neurites and reduced cell body diameter, compared with controls. Dose-related reduction of neurite length was observed in mycolactone-treated cultures. Mitochondria were distributed throughout the length of neurites and soma of control neurons, but clustered in the neurites and soma of mycolactone-treated neurons. Functional effects: Mycolactone-treated human and rat DRG neurons showed dose-related inhibition of capsaicin responses, which were reversed by calcineurin inhibitor cyclosporine and phosphodiesterase inhibitor 3-isobutyl-1-Methylxanthine, indicating involvement of cAMP/ATP reduction. The morphological and functional effects of mycolactone were not altered by Angiotensin II or AT2R antagonist EMA401. CONCLUSION: Mycolactone induces toxic effects in DRG neurons, leading to impaired nociceptor function, neurite degeneration, and cell death, resembling the cutaneous hypoalgesia and nerve damage in individuals with M. Ulcerans infection.

Association between joint hypermobility and pelvic organ prolapse in women: a systematic review and meta-analysis.

INTRODUCTION AND HYPOTHESIS: Abnormalities of common collagen proteins have been noted in individuals affected by POP and JHM, suggesting a common aetiology. We assessed strength, consistency and potential for bias in pooled associations of the relationship between JHM and POP. METHODS: We searched MEDLINE, EMBASE and CINAHL, as well as International Continence Society (ICS) and International Urogynaecologic Association (IUGA) annual meeting abstracts, including reference lists, without language restrictions. We included case-control and cohort studies and applied strict criteria for choosing eligible studies. Methodologically trained reviewers independently screened abstracts and full texts to confirm eligibility. We extracted data on study and patient characteristics, clinical assessment tools, and methodology. We assessed comparability and representativeness of source populations, confidence in the assessment of JHM and POP and adjustment for confounding and missing data. Meta-analysis was performed using a random effects model. RESULTS: We retrieved 39 full texts, of which 14 were used in the meta-analysis. Overall pooled odds ratio (OR) was 2.37 [95 % confidence interval (CI) 1.54-3.64, I(2) = 77.0 %]. We identified no significant factors in meta-regression, and there was no evidence of publication bias; six studies were at high risk of bias with frequent differences in sampling frames, limited validity for clinical assessments and failure to match for important prognostic variables. CONCLUSIONS: We found a strong association between POP and JHM, with an effect size that is clinically relevant. Our findings are limited by high heterogeneity and the potential for residual confounding factors. JHM is an important early indicator for POP risk, and future longitudinal studies should explore the shared aetiology.

An unusual case of disseminated neuroendocrine tumor presenting with generalized lymphadenopathy.

A 64-year-old male presented to the surgical out-patient department with multiple enlarged lymph nodes in the neck and axillae. As a routine practice in India, this patient was worked up on the lines of generalized lymphadenopathy with a provisional diagnosis of tuberculosis and lymphoma. The report of fine-needle aspiration cytology (FNAC) came as a surprise and on further work-up it turned out to be that the patient had disseminated neuroendocrine tumor from an unknown primary.

Angiotensin II type 2 receptor (AT2 R) localization and antagonist-mediated inhibition of capsaicin responses and neurite outgrowth in human and rat sensory neurons.

BACKGROUND: The angiotensin II (AngII) receptor subtype 2 (AT2 R) is expressed in sensory neurons and may play a role in nociception and neuronal regeneration. METHODS: We used immunostaining with characterized antibodies to study the localization of AT2 R in cultured human and rat dorsal root ganglion (DRG) neurons and a range of human tissues. The effects of AngII and AT2 R antagonist EMA401 on capsaicin responses in cultured human and rat (DRG) neurons were measured with calcium imaging, on neurite length and density with Gap43 immunostaining, and on cyclic adenosine monophosphate (cAMP) expression using immunofluorescence. RESULTS: AT2 R expression was localized in small-/medium-sized cultured neurons of human and rat DRG. Treatment with the AT2 R antagonist EMA401 resulted in dose-related functional inhibition of capsaicin responses (IC50 = 10 nmol/L), which was reversed by 8-bromo-cAMP, and reduced neurite length and density; AngII treatment significantly enhanced capsaicin responses, cAMP levels and neurite outgrowth. The AT1 R antagonist losartan had no effect on capsaicin responses. AT2 R was localized in sensory neurons of human DRG, and nerve fibres in peripheral nerves, skin, urinary bladder and bowel. A majority sub-population (60%) of small-/medium-diameter neuronal cells were immunopositive in both control post-mortem and avulsion-injured human DRG; some very small neurons appeared to be intensely immunoreactive, with TRPV1 co-localization. While AT2 R levels were reduced in human limb peripheral nerve segments proximal to injury, they were preserved in painful neuromas. CONCLUSIONS: AT2 R antagonists could be particularly useful in the treatment of chronic pain and hypersensitivity associated with abnormal nerve sprouting.

Elastomeric impression materials: a comparison of accuracy of multiple pours.

AIM: The aim of the present study is to compare the various elastomeric impression materials in terms of accuracy and dimensional stability, with respect to obtaining multiple casts from a single elastomeric impression at various times of pours. MATERIALS AND METHODS: Three master dies were prepared for the impression making, two of these were made of brass containing a central hole with undercuts. The third die simulated a conventionally prepared typodont maxillary central incisor. Three elastomeric impression materials were chosen for the study. Each impression was poured at various time periods. Casts thus obtained were evaluated under a traveling microscope to evaluate various dimensional changes. RESULTS: Addition silicones provided dies which were shorter in height and bigger in diameter. Polyethers provided dies which were shorter in both height and diameter. Condensation silicones showed insignificant changes from the master die at the immediate pour but deteriorated rapidly after that in subsequent pours. CONCLUSION: None of the impression material showed a consistent behavior up to the fourth pour. They occasionally showed deviation from the pattern, but all these values were statistically insignificant. Polyethers showed lesser ability than both the addition silicones as well as the condensation silicones to recover from induced deformation. CLINICAL SIGNIFICANCE: Addition silicones as well as the condensation silicones have better ability to recover from induced deformation when compared to polyether.

A comparative study of impression procedures for distal extension removable partial dentures.

AIM: This study was carried out with the purpose of comparing three impression methods as to which of them placed tissues most favorably. METHODS: The methods used were Hindels method, selective tissue placement method and functional reline method. The measurements obtained were analyzed to determine which of the three impression methods placed the mucosal tissues maximally. To compare and measure tissue placements, autopolymerizing acrylic resin platforms were constructed to the height of the occlusal surfaces of the remaining teeth. 15 orthodontic buccal tubes were placed on each side of the platform. They were arranged in three sets of five and attached to the platform over selected reference regions by means of autopolymerizing resin. The selected reference areas were in anterior, middle and posterior areas of the ridge on either side. RESULTS: No significant difference was seen in tissue placement in the anterior middle and posterior regions in each of the three methods when each method was assessed separately. Selective tissue placement method placed the tissues maximally (7.547 mm) followed by Hindels method (7.2110 mm) and the least placement was by functional reline method (5.856 mm). Tissue placement was significantly higher in Hindels method as compared to functional reline method (p < 0.001). CONCLUSION: Tissue placement was maximum in the posterior region, followed by the middle region and least in the anterior region of the mandibular ridge for all three methods. Selective tissue placement method showed the maximum overall tissue placement followed by the Hindels method and minimum placement was by functional reline method. CLINICAL SIGNIFICANCE: Selective tissue placement method provided maximum overall tissue placement and can be a preferred technique for impression making for bilateral distal extension removable partial denture fabrication.

Beware the perianal granuloma! A case report.

BACKGROUND: Crohn's disease (CD) can often present initially with extraintestinal manifestations and/or perianal disease. Cytology of such a lesion helps arrive at the diagnosis. CASE: A 27-year-old woman presented with recurrent, painful, discharging perianal lesions. On examination, multiple perianal abscesses, sinuses, skin tags and healed scars were noted. Fine needle aspiration cytology (FNAC) of the perianal lesions performed as a first line investigation revealed epithelioid granulomas in a suppurative background. The possibility of tuberculosis vs. extraintestinal manifestation of CD was considered. Endoscopic studies revealed involvement of distal ileum and the entire colon by deep, serpiginous ulcers, internal fistulae and a distorted ileocecal valve. Biopsy of the intestinal lesions revealed chronic inflammation, aphthous ulcers and microgranulomas, favoring a diagnosis of CD. CONCLUSION: A granulomatous lesion in any location arouses the clinical suspicion of tuberculosis, given its prevalence in the Indian subcontinent. In view of the increasing incidence of CD in our setting, the finding of a perianal, granulomatous lesion on cytology should prompt a workup for CD in addition to the more common granulomatous counterpart, tuberculosis. Perianal aspiration is an underused diagnostic procedure that can help in narrowing the differential diagnostic possibilities.

Alkali-stabilized Pt-OHx species catalyze low-temperature water-gas shift reactions.

We report that alkali ions (sodium or potassium) added in small amounts activate platinum adsorbed on alumina or silica for the low-temperature water-gas shift (WGS) reaction (H(2)O + CO → H(2) + CO(2)) used for producing H(2). The alkali ion-associated surface OH groups are activated by CO at low temperatures (~100°C) in the presence of atomically dispersed platinum. Both experimental evidence and density functional theory calculations suggest that a partially oxidized Pt-alkali-O(x)(OH)(y) species is the active site for the low-temperature Pt-catalyzed WGS reaction. These findings are useful for the design of highly active and stable WGS catalysts that contain only trace amounts of a precious metal without the need for a reducible oxide support such as ceria.

Effect of hemodialysis on circulating cystatin c levels in patients with end stage renal disease.

Plasma cystatin C is an emerging parameter to assess kidney function. Its utility in assessing the adequacy of hemodialysis in patients with end-stage-renal disease has however not been established with certainty. This study was therefore carried out to assess the usefulness of serum cystatin C estimation in patients undergoing low flux membrane hemodialysis. Serum creatinine and cystatin C were estimated in 20 patients before and after undergoing hemodialysis. The mean serum creatinine decreased from a pre-dialysis value of 7.72 mg/dL to a post-dialysis value of 2.90 mg/dL. On the contrary, the mean serum cystatin C levels were found to increase from a pre-dialysis value of 5.97 mg/L to a post-dialysis value of 8.25 mg/L. Therefore, serum cystatin C cannot be used to monitor dialysis adequacy. It however, serves as a surrogate marker of the inadequacy of low flux membrane bicarbonate hemodialysis in clearing low molecular weight proteins from the circulation.

TRPA1 receptor localisation in the human peripheral nervous system and functional studies in cultured human and rat sensory neurons.

TRPA1 is a receptor expressed by sensory neurons, that is activated by low temperature (<17 degrees C) and plant derivatives such as cinnamaldehyde and isoeugenol, to elicit sensations including pain. Using immunohistochemistry, we have, for the first time, localised TRPA1 in human DRG neurons, spinal cord motoneurones and nerve roots, peripheral nerves, intestinal myenteric plexus neurones, and skin basal keratinocytes. TRPA1 co-localised with a subset of hDRG neurons positive for TRPV1, the heat and capsaicin receptor. The number of small/medium TRPA1 positive neurons (< or =50 microm) was increased after hDRG avulsion injury [percentage of cells, median (range): controls 16.5 (7-23); injured 46 (34-55); P<0.005], but the number of large TRPA1 neurons was unchanged [control 19.5 (13-31); injured 21 (11-35)]. Similar TRPA1 changes were observed in cultured hDRG neurons, after exposure to a combination of key neurotrophic factors NGF, GDNF and NT-3 (NTFs) in vitro. We used calcium imaging to examine responses of HEK cells transfected with hTRPA1 cDNA, and of human and rat DRG neurons cultured with or without added NTFs, to cinnamaldehyde (CA) and isoeugenol (IE). Exposure to NTFs in vitro sensitized cultured human sensory neuronal responses to CA; repeated CA exposure produced desensitisation. In rDRG neurons, low (225 microM) CA preincubation enhanced capsaicin responses, while high (450 microM and 2mM) CA caused inhibition which was partially reversed in the presence of 8 bromo cAMP, indicating receptor dephosphorylation. While TRPA1 localisation is more widespread than TRPV1, it represents a promising novel drug target for the treatment of chronic pain and hypersensitivity.

Ru-Pt core-shell nanoparticles for preferential oxidation of carbon monoxide in hydrogen.

Most of the world's hydrogen supply is currently obtained by reforming hydrocarbons. 'Reformate' hydrogen contains significant quantities of CO that poison current hydrogen fuel-cell devices. Catalysts are needed to remove CO from hydrogen through selective oxidation. Here, we report first-principles-guided synthesis of a nanoparticle catalyst comprising a Ru core covered with an approximately 1-2-monolayer-thick shell of Pt atoms. The distinct catalytic properties of these well-characterized core-shell nanoparticles were demonstrated for preferential CO oxidation in hydrogen feeds and subsequent hydrogen light-off. For H2 streams containing 1,000 p.p.m. CO, H2 light-off is complete by 30 (composite function)C, which is significantly better than for traditional PtRu nano-alloys (85 (composite function)C), monometallic mixtures of nanoparticles (93 (composite function)C) and pure Pt particles (170 ( composite function)C). Density functional theory studies suggest that the enhanced catalytic activity for the core-shell nanoparticle originates from a combination of an increased availability of CO-free Pt surface sites on the Ru@Pt nanoparticles and a hydrogen-mediated low-temperature CO oxidation process that is clearly distinct from the traditional bifunctional CO oxidation mechanism.