Process evaluation of a complex, multilevel, multicomponent scheme for the prevention and control of non-communicable diseases in Tamil Nadu, India: A mixed-methods protocol.

Background: Non-communicable diseases (NCDs) are the leading cause of morbidity and mortality in India, necessitating development of multilevel and multicomponent interventions. Makkalai Thedi Maruthuvam (MTM) is a complex multilevel, multicomponent intervention developed and implemented by the south Indian State of Tamil Nadu. The scheme aims to deliver services for preventing and controlling diabetes, and hypertension at doorstep. This paper describes the protocol for planning and conducting the process evaluation of the MTM scheme. Methods and analysis: The process evaluation uses mixed methods (secondary data analysis, key informant interviews, in-depth interviews, conceptual content analysis of documents, facility-based survey and non-participant observation) to evaluate the implementation of the MTM scheme. The broad evaluation questions addressed the fidelity, contexts, mechanisms of impact and challenges encountered by the scheme using the Consolidated Framework for Implementation Research (CFIR) framework. The specific evaluation questions addressed selected inputs and processes identified as critical to implementation by the stakeholders. The CFIR framework will guide the thematic analysis of the qualitative interviews to explore the adaptations and deviations introduced during implementation in various contexts. The quantitative data on the indicators developed for the specific evaluation questions will be cleaned and descriptively analysed.

Clinical and neurocognitive outcomes after transcatheter aortic valve implantation (TAVI) with cerebral protection: initial experience with a novel dual-filter device in Southeast Asia.

INTRODUCTION: Transcatheter aortic valve implantation (TAVI) is increasingly performed in patients with severe aortic stenosis. A novel dual-filter system to reduce cerebral embolism during TAVI recently became available. We aimed to assess the feasibility, safety, and clinical and neurocognitive outcomes of TAVI with cerebral protection in Asian patients. METHODS: 40 consecutive patients undergoing TAVI with cerebral protection were enrolled. All procedures were performed via femoral access using the self-expanding Evolut R/PRO or Portico, or the balloon-expandable SAPIEN 3 bioprostheses. Baseline characteristics, procedural and clinical outcomes were recorded. Cognition was assessed at baseline and 30 days using the abbreviated mental test (AMT). RESULTS: The mean age of the patients (75% male) was 76.4 ± 8.4 years. TAVI was uncomplicated in all patients. The filter device was successfully deployed in 38 (95.0%) patients without safety issues. There was no stroke or death at 30 days, and the survival rate at nine months was 95.0%. There was no overall cognitive change (baseline vs. 30-day AMT: 9.2 ± 1.1 vs. 9.0 ± 1.5, p = 0.12), and only 1 (2.5%) patient developed impaired cognition at 30 days. Patients with a decreased AMT score at 30 days were significantly older than those without (82.1 ± 4.5 vs. 74.4 ± 7.7 years, p = 0.019). All patients with decreased AMT scores were aged ≥ 76 years. CONCLUSION: In this early Asian experience of TAVI under cerebral protection, the filter device was successfully deployed in 95% of patients, with 100% procedural success. There were no filter-related complications and no stroke or mortality at 30 days. Overall cognition was preserved, although increased age was associated with a decline in AMT score.

Induction of smell through transethmoid electrical stimulation of the olfactory bulb.

BACKGROUND: Anosmia has an estimated prevalence of 5% of the general population. Outside of inflammatory causes, therapeutic options are limited despite research advances. Bypassing peripheral neuronal damage through central stimulation is a potential therapeutic option that has shown success in other sensory systems, most notably with hearing. We performed a pilot study to determine the feasibility of inducing smell through artificial electrical stimulation of the olfactory bulbs in humans. METHODS: Subjects with a history of sinus surgery, including total ethmoidectomy, with intact ability to smell were enrolled. The ability to smell was confirmed with a 40-item smell identification test. Awake subjects underwent nasal endoscopy and either a monopolar or bipolar electrode was positioned at 3 areas along the lateral lamella of the cribriform plate within the ethmoid sinus cavity. A graded stimulation current of 1-20 mA at 3.17 Hz was administered while cortical evoked potential (CEP) recordings were collected. Subjective responses of perceived smell along with reports of discomfort were recorded. Subjects with artificially induced smell underwent repeat stimulation after medically induced anosmia. RESULTS: Five subjects (age, 43-72 years) were enrolled. Three subjects reported smell perception smell with electrical stimulation. This was reproducible after inducing anosmia, but CEP recordings could not provide objective support. All subjects tolerated the study with minimal discomfort. CONCLUSION: This is the first report of induced smell through transethmoid electrical stimulation of the olfactory bulb. These results provide a proof of concept for efforts in development of an olfactory implant system.

Assessment of Retention and Resistance Form of Tooth Preparations for All Ceramic Restorations using Digital Imaging Technique.

AIM: This in vitro study evaluated the resistance form of die preparations for all ceramic restorations and, thereby, explored the concept of effective taper and its correlation between the ideal in theory and actual in the clinical situation by analyzing the digital images of the die preparations. MATERIALS AND METHODS: Scanned digital images of 114 die preparations for all ceramic restorations (n = 114) were collected from a dental laboratory. All the images were also analyzed digitally using Adobe Photoshop® software to analyze the degree of taper (angle of convergence) of each preparation and then applied the Zuckerman's circle, and the Lewis perpendicular methods were used to measure the resistance form. RESULTS: For the current study, the overall average degree of taper was found to be 20.9° (range, 2-80°), which is more than what is recommended by most previous studies and also sharply greater than the textbook ideal of 3 to 6°. Mean degree of taper for maxillary was 17.56° (anterior-10.50°, posterior-23.7°), and for mandibular teeth, it was 25.22° (anterior-15°, posterior- 28.45°). Out of the 64 analyzed images of maxillary teeth, 61 presented resistance form, while 3 were without it. Out of the 50 mandibular teeth analyzed, 38 possessed resistance form, whereas 12 were without. All the anterior teeth showed resistance form irrespective of the arch. CONCLUSION: The degree of taper showed a significant relationship with resistance and retention form, which was inversely proportional to each other. The recommended "degree of taper" is not always the clinically achievable as advocated in textbooks, as it is modified by various factors in the actual clinical situation. CLINICAL SIGNIFICANCE: The study provides scientific background regarding the relationship between the degree of taper with resistance and retention form, and the relationship was found to be inversely proportional to each other. The recommended "degree of taper" is not always the clinically achievable as advocated in textbooks, and it is modified by various modifying or limiting factors in the actual clinical situation.

Cost-effectiveness of health systems strengthening interventions in improving maternal and child health in low- and middle-income countries: a systematic review.

Health systems strengthening (HSS) interventions are increasingly being implemented to improve maternal and child health (MCH) services in low- and middle-income countries (LMICs). This study reviews global literature on cost-effectiveness of HSS interventions in improving MCH. A systematic review was conducted. Keywords, based on World Health Organization framework on health systems and prior studies, were applied to search in bibliographic databases and on the web. Articles that estimated cost-effectiveness of HSS interventions in LMICs were included in the analysis. Each of the 24 selected studies from 15 countries was assessed in terms of quality and biases using Cochrane's criteria. Review Manager and an Excel template were used to extract data and synthesize findings. HSS interventions concentrated on the components of service delivery, health financing, human resources and quality improvement. Within each component, there existed diverse strategies to strengthen health systems. Among the 24 studies, 15 were rated as high quality, 5 as medium and 4 as low quality. A majority of studies reported cost per disability-adjusted life year (DALY) averted or cost per quality-adjusted life year (QALY) gained; other studies reported cost per life saved or life year gained. However, studies used mixed perspectives of analyses. Compared with gross domestic product per capita, interventions in studies reporting cost per DALY averted or QALY gained were all cost-effective, including performance-based financing, health insurance and quality improvement. This review shows the diversity of HSS interventions in improving MCH, and their potential cost-effectiveness. However, the different perspectives employed in the studies, costing components included in the analyses, and heterogeneous measures of effectiveness and outputs, made it challenging to compare cost-effectiveness across all studies, calling for more and standardized cost-effectiveness studies. For policy making, it is critical to examine long-term cost-effectiveness of programs and cost-effectiveness of synergistic demand- and supply-side interventions.

Dielectric, thermal and mechanical properties of zirconium silicate reinforced high density polyethylene composites for antenna applications.

A low cost and low dielectric loss zirconium silicate (ZrSiO4) reinforced HDPE (high-density polyethylene) composite has been developed for antenna applications. The 0-3 type composite is prepared by dispersing ZrSiO4 fillers for various volume fractions (0.1 to 0.5) in the HDPE matrix by the melt mixing process. The composite shows good microwave dielectric properties with a relative permittivity of 5.6 and a dielectric loss of 0.003 at 5 GHz at the maximum filler loading of 0.5 volume fraction. The composite exhibits low water absorption, excellent thermal and mechanical properties. It shows a water absorption of 0.03 wt%, a coefficient of thermal expansion of 70 ppm per °C and a room temperature thermal conductivity of 2.4 W mK(-1). The composite shows a tensile strength of 22 MPa and a microhardness of 13.9 kg mm(-2) for the filler loading of 0.5 volume fraction. The HDPE-ZrSiO4 composites show good dielectric, thermal and mechanical properties suitable for microwave soft substrate applications. A microstrip patch antenna is designed and fabricated using the HDPE-0.5 volume fraction ZrSiO4 substrate and the antenna parameters are investigated.

Intraoperative somatosensory evoked potential monitoring decreases EEG burst suppression ratio during deep general anesthesia.

PURPOSE: The burst suppression (BS) EEG patterns induced by general anesthesia can react to somatosensory stimuli. We investigated this reactivity by studying the effect of peripheral nerve stimulation used for routine intraoperative spinal cord monitoring by somatosensory evoked potentials on BS patterns. METHODS: The relative time spent in suppression expressed as BS ratio (BSR) and mean burst duration were measured before (BSR(Pre)), during (BSR(Stim)), and after (BSR(Post)) a 60-second repetitive electrical ulnar nerve stimulation in nine patients under total intravenous general anesthesia with propofol. The BS reactivity was measured as BSR(Pre)-BSR(Stim). RESULTS: Overall, 27 trials were included with BSR(Pre) up to 77%, indistinguishable from BSR(Post). During stimulation, the mean BSR transiently decreased from 42% to 35%. For each 1% increase in BSR(Pre), the BS reactivity increased with 0.6%, whereas the burst duration remained approximately 3 seconds. For BSR(Pre) below 30%, the BS reactivity was negligible. CONCLUSIONS: Data from this study show that somatosensory input can evoke bursts, altering the "spontaneous" deep BS patterns (BSR(Pre) >30%). Further studies are necessary to objectively assess the clinical relevance of stimulus-induced BS reactivity during deep general anesthesia.

Dorsal column mapping via phase reversal method: the refined technique and clinical applications.

BACKGROUND: Safe resection of intramedullary spinal cord tumors can be challenging, because they often alter the cord anatomy. Identification of neurophysiologically viable dorsal columns (DCs) and of neurophysiologically inert tissue, eg, median raphe (MR), as a safe incision site is crucial for avoiding postoperative neurological deficits. We present our experience with and improvements made to our previously described technique of DC mapping, successfully applied in a series of 12 cases. OBJECTIVE: To describe a new, safe, and reliable technique for intraoperative DC mapping. METHODS: The right and left DCs were stimulated by using a bipolar electric stimulator and the triggered somatosensory evoked potentials recorded from the scalp. Phase reversal and amplitude changes of somatosensory evoked potentials were used to neurophysiologically identify the laterality of DCs, the inert MR, as well as other safe incision sites. RESULTS: The MR location was neurophysiologically confirmed in all patients in whom this structure was first visually identified as well as in those in whom it was not, with 1 exception. DCs were identified in all patients, regardless of whether they could be visually identified. In 3 cases, negative mapping with the use of this method enabled the surgeon to reliably identify additional inert tissue for incision. None of the patients had postoperative worsening of the DC function. CONCLUSION: Our revised technique is safe and reliable, and it can be easily incorporated into routine intramedullary spinal cord tumor resection. It provides crucial information to the neurosurgeon to prevent postoperative neurological deficits.

Intraoperative mapping of roots, plexuses, and nerves.

The use of intraoperative mapping of neural structures has come to be an indispensable technique to prevent or minimize postoperative morbidity. In this article, I briefly mention its use in mapping nerve roots, plexuses, and peripheral nerves. The reader may find some mention of monitoring techniques, too, as monitoring and mapping are seldom done separately. I include the technical details of different mapping modalities, relevant anatomy, and clinical applications, as appropriate.

Optimizing recovery potential through simultaneous occupational therapy and non-invasive brain-stimulation using tDCS.

PURPOSE: It is thought that following a stroke the contralesional motor region exerts an undue inhibitory influence on the lesional motor region which might limit recovery. Pilot studies have shown that suppressing the contralesional motor region with cathodal transcranial Direct Current Stimulation (tDCS) can induce a short lasting functional benefit; greater and longer lasting effects might be achieved with combining tDCS with simultaneous occupational therapy (OT) and applying this intervention for multiple sessions. METHODS: We carried out a randomized, double blind, sham controlled study of chronic stroke patients receiving either 5 consecutive days of cathodal tDCS (for 30 minutes) applied to the contralesional motor region and simultaneous OT, or sham tDCS+OT. RESULTS: we showed that cathodal tDCS+OT resulted in significantly more improvement in Range-Of-Motion in multiple joints of the paretic upper extremity and in the Upper-Extremity Fugl-Meyer scores than sham tDCS+OT, and that the effects lasted at least one week post-stimulation. Improvement in motor outcome scores was correlated with decrease in fMRI activation in the contralesional motor region exposed to cathodal stimulation. CONCLUSIONS: This suggests that cathodal tDCS combined with OT leads to significant motor improvement after stroke due to a decrease in the inhibitory effect that the contralesional hemisphere exerts onto the lesional hemisphere.

Transcranial direct current stimulation in stroke recovery.

Transcranial direct current stimulation (TDCS) is an emerging technique of noninvasive brain stimulation that has been found useful in examining cortical function in healthy subjects and in facilitating treatments of various neurologic disorders. A better understanding of adaptive and maladaptive poststroke neuroplasticity and its modulation through noninvasive brain stimulation has opened up experimental treatment options using TDCS for patients recovering from stroke. We review the role of TDCS as a facilitator of stroke recovery, the different modes of TDCS, and the potential mechanisms underlying the neural effects of TDCS.

Modulating activity in the motor cortex affects performance for the two hands differently depending upon which hemisphere is stimulated.

We modulated neural excitability in the human motor cortex to investigate behavioral effects for both hands. In a previous study, we showed that decreasing excitability in the dominant motor cortex led to a decline in performance for the contralateral hand and an improvement for the ipsilateral hand; increasing excitability produced the opposite effects. Research suggests that the ipsilateral effects were mediated by interhemispheric inhibition. Physiological evidence points to an asymmetry in interhemispheric inhibition between the primary motor cortices, with stronger inhibitory projections coming from the dominant motor cortex. In the present study, we examined whether there is a hemispheric asymmetry in the effects on performance when modulating excitability in the motor cortex. Anodal and cathodal transcranial direct current stimulation were applied to the motor cortex of 17 participants, targeting the non-dominant hemisphere on one day and the dominant hemisphere on another day, along with one sham session. Participants performed a finger-sequence coordination task with each hand before and after stimulation. The dependent variable was calculated as the percentage of change in the number of correct keystrokes. We found that the effects of transcranial direct current stimulation depended upon which hemisphere was stimulated; modulating excitability in the dominant motor cortex significantly affected performance for the contralateral and ipsilateral hands, whereas modulating excitability in the non-dominant motor cortex only had a significant impact for the contralateral hand. These results provide evidence for a hemispheric asymmetry in the ipsilateral effects of modulating excitability in the motor cortex and may be important for clinical research on motor recovery.

Progress and current status of percutaneous aortic valve replacement: results of three device generations of the CoreValve Revalving system.

BACKGROUND: Percutaneous aortic valve replacement is a new emerging technology for interventional treatment of severe aortic valve stenosis in surgical high-risk patients. This study was intended to provide a summary of the development and current safety and efficacy status of the self-expanding CoreValve Revalving prosthesis. METHOD AND RESULTS: Between 2005 and 2008, we have enrolled 136 consecutive patients with percutaneous aortic valve replacement using the CoreValve prosthesis. In this prospective nonrandomized, single-center trial, we analyzed procedural outcome, complications and clinical status up to 1 year. First, second, and third generation of the CoreValve prosthesis were implanted in 10, 24, and 102 consecutive high-risk patients (logistic EuroScore: 23.1+/-15.0%) with severe symptomatic aortic valve stenosis. Mean transvalvular pressure gradient was 41.5+/-16.7 mm Hg. The procedural success rate increased from generation 1/2 to 3 from 70.0%/70.8% to 91.2% (P=0.003). The 30-day combined rate of death/stroke/myocardial infarction was 40.0%/20.8%/14.7% (P=0.11) for generation 1, 2, and 3, with no procedural death in generation 3. Pressure gradients improved significantly with a final mean gradient of 8.1+/-3.8 mm Hg. Overall functional status assessed by New York Heart Association class improved from 3.3+/-0.5 (pre) to 1.7+/-0.7 (post) (P<0.001) and remained stable in the follow-up. CONCLUSIONS: In experienced hands, percutaneous aortic valve replacement with the CoreValve system for selected patients with severe aortic valve stenosis has a high acute success rate associated with a low periprocedural mortality/stroke rate as well as remarkable clinical and hemodynamic improvements, which persist over time. Additional studies are now required to confirm these findings, particularly head-to-head comparisons with surgical valve replacement in different risk populations.

Imaging correlates of motor recovery from cerebral infarction and their physiological significance in well-recovered patients.

We studied motor representation in well-recovered stroke patients. Eighteen right-handed stroke patients and eleven age-matched control subjects underwent functional Magnetic Resonance Imaging (fMRI) while performing unimanual index finger (abduction-adduction) and wrist movements (flexion-extension) using their recovered and non-affected hand. A subset of these patients underwent Transcranial Magnetic Stimulation (TMS) to elicit motor evoked potentials (MEP) in the first dorsal interosseous muscle of both hands. Imaging results suggest that good recovery utilizes both ipsi- and contralesional resources, although results differ for wrist and index finger movements. Wrist movements of the recovered arm resulted in significantly greater activation of the contralateral (lesional) and ipsilateral (contralesional) primary sensorimotor cortex (SM1), while comparing patients to control subjects performing the same task. In contrast, recovered index finger movements recruited a larger motor network, including the contralateral SM1, Supplementary Motor Area (SMA) and cerebellum when patients were compared to control subjects. TMS of the lesional hemisphere but not of the contralesional hemisphere induced MEPs in the recovered hand. TMS parameters also revealed greater transcallosal inhibition, from the contralesional to the lesional hemisphere than in the reverse direction. Disinhibition of the contralesional hemisphere observed in a subgroup of our patients suggests persistent alterations in intracortical and transcallosal (interhemispheric) interactions, despite complete functional recovery.

Contralateral and ipsilateral motor effects after transcranial direct current stimulation.

Transcranial direct current stimulation over the left motor area influenced both contralateral and ipsilateral finger sequence movements in seven healthy adults. Effects for the two hands were reversed: anodal stimulation improved right-hand performance significantly more than cathodal stimulation, whereas cathodal stimulation improved left-hand performance significantly more than anodal stimulation. The results show that stimulating a motor region directly, or indirectly by modulating activity in the homologous region on the opposite hemisphere, can affect motor skill acquisition, presumably by facilitating effective synaptic connectivity. This outcome provides evidence for the role of interhemispheric inhibition in corticomotor functioning, and also has implications for treatment methods aimed at facilitating motor recovery after stroke.

About being BOLD.

The last decade has seen an unprecedented increase in the use of functional magnetic resonance imaging (fMRI) to understand the neural basis of cognition and behavior. Being non-invasive and relatively easy to use, most studies relied on changes in the blood oxygenation level dependent (BOLD) contrast as an indirect marker of variations in brain activity. However, the fact that BOLD fMRI is dependent on the blood flow response that follows neural activity and does not measure neural activity per se is seen as an inherent cause for concern while interpreting data from these studies. In order to characterize the BOLD signal correctly, it is imperative that we have a better understanding of neural events that lead to the BOLD response. A review of recent studies that addressed several aspects of BOLD fMRI including events at the level of the synapse, the nature of the neurovascular coupling, and some parameters of the BOLD signal is provided. This is intended to serve as background information for the interpretation of fMRI data in normal subjects and in patients with compromised neurovascular coupling. One of the aims is also to encourage researchers to interpret the results of functional imaging studies in light of the dynamic interactions between different brain regions, something that often is neglected.

Membrane separation in green chemical processing: solvent nanofiltration in liquid phase organic synthesis reactions.

This paper describes ideas together with preliminary experimental results for applying solvent nanofiltration to liquid phase organic synthesis reactions. Membranes for organic solvent nanofiltration have only recently (during the 1990s) become available and, to date, have been applied primarily to food processing (vegetable oil processing, in particular) and refinery processes. Applications to organic synthesis, even at a laboratory feasibility level, are few. However, these membranes have great potential to improve the environmental performance of many liquid phase synthesis reactions by reducing the need for complex solvent handling operations. Examples that are shown to be feasible are solvent exchanges, where it is desired to swap a high molecular weight molecule from one solvent to another between separate stages in a complex synthesis, and recycle and reuse of homogeneous catalysts. In solvent exchanges, nanofiltration is shown to provide a fast and effective means of swapping from a high boiling point solvent to a solvent with a lower boiling point-this is a difficult operation by means of distillation. Solvent nanofiltration is shown to be able to separate two distinct types of homogeneous catalysts, phase transfer catalysts and organometallic catalysts, from their respective reaction products. In both cases the application of organic solvent nanofiltration allows several reuses of the same catalyst. Catalyst stability is shown to be an essential requirement for this technique to be effective. Finally, we present a discussion of scale-up aspects including membrane flux and process economics.