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1.
Adv Mater ; 35(40): e2302442, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37399104

ABSTRACT

Hydrochromic materials that change their luminescence color upon exposure to moisture have attracted considerable attention owing to their applications in sensing and information encryption. However, the existing materials lack high hydrochromic response and color tunability. This study reports the development of a new and bright 0D Cs3 GdCl6 metal halide as the host for hydrochromic photon upconversion in the form of polycrystals (PCs) and nanocrystals. Lanthanides co-doped cesium gadolinium chloride metal halides exhibit upconversion luminescence (UCL) in the visible-infrared region upon 980 nm laser excitation. In particular, PCs co-doped with Yb3+ and Er3+ exhibit hydrochromic UCL color change from green to red. These hydrochromic properties are quantitatively confirmed through the sensitive detection of water in tetrahydrofuran solvent via UCL color changes. This water-sensing probe exhibits excellent repeatability and is particularly suitable for real-time and long-term water monitoring. Furthermore, the hydrochromic UCL property is exploited for stimuli-responsive information encryption via cyphertexts. These findings will pave the way for the development of new hydrochromic upconverting materials for emerging applications, such as noncontact sensors, anti-counterfeiting, and information encryption.

2.
Hernia ; 27(5): 1235-1243, 2023 10.
Article in English | MEDLINE | ID: mdl-37310493

ABSTRACT

INTRODUCTION: The practice of inguinal hernia repair varies internationally. The global practice of inguinal hernia repair study (GLACIER) aimed to capture these variations in open, laparoscopic, and robotic inguinal hernia repair. METHODS: A questionnaire-based survey was created on a web-based platform, and the link was shared on various social media platforms, personal e-mail network of authors, and e-mails to members of the endorsed organisations, which include British Hernia Society (BHS), The Upper Gastrointestinal Surgical Society (TUGSS), and Abdominal Core Health Quality Collaborative (ACHQC). RESULTS: A total of 1014 surgeons from 81 countries completed the survey. Open and laparoscopic approaches were preferred by 43% and 47% of participants, respectively. Transabdominal pre-peritoneal repair (TAPP) was the favoured minimally invasive approach. Bilateral and recurrent hernia following previous open repair were the most common indications for a minimally invasive procedure. Ninety-eight percent of the surgeons preferred repair with a mesh, and synthetic monofilament lightweight mesh with large pores was the most common choice. Lichtenstein repair was the most favoured open mesh repair technique (90%), while Shouldice repair was the favoured non-mesh repair technique. The risk of chronic groin pain was quoted as 5% after open repair and 1% after minimally invasive repair. Only 10% of surgeons preferred to perform an open repair using local anaesthesia. CONCLUSION: This survey identified similarities and variations in practice internationally and some discrepancies in inguinal hernia repair compared to best practice guidelines, such as low rates of repair using local anaesthesia and the use of lightweight mesh for minimally invasive repair. It also identifies several key areas for future research, such as incidence, risk factors, and management of chronic groin pain after hernia surgery and the clinical and cost-effectiveness of robotic hernia surgery.


Subject(s)
Hernia, Inguinal , Laparoscopy , Surgeons , Humans , Hernia, Inguinal/surgery , Ice Cover , Herniorrhaphy/methods , Surgical Mesh/adverse effects , Laparoscopy/methods , Pain/surgery
3.
Nanoscale ; 13(33): 14186-14196, 2021 Sep 07.
Article in English | MEDLINE | ID: mdl-34477700

ABSTRACT

Cesium lead iodide (CsPbI3) perovskite nanocrystals (NCs) suffer from a known transformation at room temperature from their red-emitting (black) to non-emitting (yellow) phase, induced by the tilting of PbI6 octahedra. While the reported attempts to stabilize CsPbI3 NCs mainly involve Pb2+-site doping as well as compositional and/or NC surface engineering, the black phase stability in relation only to the variation of the reaction temperature of CsPbI3 NCs is surprisingly overlooked. We report a holistic study of the phase stability of CsPbI3 NCs, encompassing dispersions, films, and even devices by tuning the hot-injection temperature between 120-170 °C. Our findings suggest that the transition from the black to the yellow phase occurs after over a month for NCs synthesized at 150 °C (150@NCs). Structural refinement studies attribute the enhanced stability of 150@NCs to their observed lowest octahedral distortion. The 150@NCs also lead to stable unencapsulated solar cells with unchanged performance upon 26 days of shelf storage in dry air. Our study underlines the importance of scrutinizing synthesis parameters for designing stable perovskite NCs towards long-lasting optoelectronic devices.

4.
J Phys Chem Lett ; 11(18): 7723-7729, 2020 Sep 17.
Article in English | MEDLINE | ID: mdl-32870687

ABSTRACT

Cesium copper halides (CCHs) show promise for optoelectronic applications, and their syntheses usually involve high-temperatures and hazard solvents. Herein, the synthesis of highly luminescent and phase-pure Cs3Cu2X5 (X = Cl, Br, and I) and CsCu2I3 via a solvent-free mechanochemical approach through manual grinding is demonstrated. This cost-effective approach can produce CCHs on a scale of tens to hundreds of grams. Rietveld refinement analysis of the X-ray diffraction patterns of the as-synthesized CCHs reveals their structural details. Notably, the emission characteristics of green-emitting, chloride-based CCHs remain stable even at elevated temperatures-maintaining 80% of initial PL efficiency at 150 °C. Lastly, a postsynthetic reversible transformation between zero- and one-dimensional CCH materials is demonstrated, indicating the labile nature of their crystal structure. The proposed study suggests that mechanochemistry can be an alternative and promising synthetic tool for fabricating high-quality lead-free metal halides.

5.
J Phys Chem Lett ; 11(9): 3699-3704, 2020 May 07.
Article in English | MEDLINE | ID: mdl-32319775

ABSTRACT

Increasing the stability of lead halide perovskites (LHPs) is required for integrating them into light-emitting devices. To date, most studies toward this direction have primarily concentrated on improving the chemical stability of green-emitting LHPs. In this work, red-emitting CsPbI3-Cs4PbI6 hybrid nanocrystals (NCs) were synthesized with a high photoluminescence (PL) quantum yield of ∼90%. Their hybrid structure was examined via structural (Rietveld) refinement analysis and transmission electron microscopy. Rietveld refinement also revealed that the black polymorph of CsPbI3 NCs is an orthorhombic perovskite rather than a cubic one. The thermodynamic stability of the CsPbI3 NCs in Cs4PbI6 matrices is enhanced in both solutions and films for up to several weeks. The enhanced stability of the embedded CsPbI3 NCs is attributed to the lowering of their Gibbs free energy, as determined on the basis of experimental data. Additionally, the hybrid NCs exhibit unprecedented emission stability-maintaining 65% of their original PL efficiency at 150 °C-and improved aqueous stability.

6.
Nanoscale ; 12(3): 2157, 2020 01 23.
Article in English | MEDLINE | ID: mdl-31939979

ABSTRACT

Correction for 'Highly stable hetero-structured green-emitting cesium lead bromide nanocrystals via ligand-mediated phase control' by G. Krishnamurthy Grandhi et al., Nanoscale, 2019, 11, 21137-21146.

7.
Nanoscale ; 11(44): 21137-21146, 2019 Nov 28.
Article in English | MEDLINE | ID: mdl-31686059

ABSTRACT

Green-emissive Cs4PbBr6 shows promise for light-emitting diode devices superior to that of CsPbBr3 NCs owing to their stability and high photoluminescence efficiency. Nevertheless, there is still no consensus regarding the basis of their green emission, which decelerates their advance in light-emitting applications. Herein, a systematic investigation on the concentration of capping ligands (oleylamine and oleic acid), which determines the predominant phase between CsPbBr3 and Cs4PbBr6 for a given Cs to Pb feed ratio, is conducted. This study deduces that oleylamine to oleic acid ratio plays a crucial role in obtaining either green-emissive or non-emissive Cs4PbBr6 NCs. Scrutiny of Cs4PbBr6 microscopic and optical data in addition to their emission quenching study with a hole-withdrawing molecule reveals that the green emission originates from the CsPbBr3 impurity phase. Furthermore, stable green emission is observed for CsPbBr3/Cs4PbBr6 nanocrystals when CsPbBr3 particles are well protected by the Cs4PbBr6 matrix. These CsPbBr3/Cs4PbBr6 films remained highly luminescent even after UV exposure for hours or annealing at ∼150 °C for days in addition to their long-term stability under an ambient atmosphere, which are the desirable properties for various practical applications.

8.
Indian J Nephrol ; 29(3): 172-178, 2019.
Article in English | MEDLINE | ID: mdl-31142963

ABSTRACT

There is only limited information on the functional status (FS) of patients receiving hemodialysis (HD) from developing countries where the etiology of chronic kidney disease (CKD) and demographic profile are different. The study aims to assess the FS in patients with CKD using three validated generic instruments. A total of 116 adult patients on HD with a dialysis vintage >3 months were enrolled. FS was assessed using three generic tools - Functional Independence Measure (FIM) (scores 18-126), Seven domains and five levels (7D5L) (scores 0-28), and Activities of Daily Living Questionnaire (ADLQ) (scores 0-6) scales. A higher FIM and ADLQ scores and lower 7D5L score indicated good FS. The mean age of patients was 41.28 ± 15.44 years. About 77.6% were males and 80.2% were unemployed. About 67.2% were receiving twice-weekly HD, and 28.4% were receiving thrice-weekly dialysis. The mean scores were 119.05 ± 11.42 with FIM, 6.44 ± 4.26 with 7D5L, and 5.51 ± 1.19 with ADL instruments. More than 80% showed full functional independence with ADLQ instrument. With FIM, the overall scores showed a tendency for functional independence, but the subdomains involving locomotion/mobility were impaired to a greater extent. The proportion of patients with full independence was less with 7D5L. We observed an inferior FS in individuals <40 years. Patients on HD were functionally independent as assessed by FIM and ADLQ instruments. However, 7D5L appeared to be better in identifying mild to moderate limitations in daily activities. The domains involving motor tasks seem to be affected to a greater extent. The current scales for assessing FS do not incorporate a time-dependent component.

9.
Eur J Pediatr Surg ; 20(4): 226-9, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20496317

ABSTRACT

BACKGROUND: Previously, concomitant antireflux surgery was performed in all neurologically impaired children undergoing gastrostomy tube placement in our department. This fundoplication procedure, not necessarily performed for symptomatic gastroesophageal reflux, increased the postoperative complications. This practice was changed and fundoplication was offered to only those children who had clear surgical indications for an antireflux procedure on follow-up after a feeding gastrostomy. METHODS: In the period from 1996 to 2007, all children who underwent gastrostomy with fundoplication were compared with those in whom feeding gastrostomy alone was done. The clinical symptoms, investigations and indications for gastrostomy and fundoplication were recorded. The children who underwent gastrostomy were followed up for symptoms of gastroesophageal reflux and the need for subsequent fundoplication was studied. The complications directly related to surgery were also studied and statistically analyzed. RESULTS: A total of 137 children had gastrostomy insertion, 60 of whom underwent fundoplication. Of these 60 children, 45 had concomitant fundoplication and gastrostomy. In the patients who had gastrostomy alone, a subsequent fundoplication procedure was required only in 17.1% (14 of 82). The complication rate as well as the severity of complications directly related to surgery was found to be higher in the gastrostomy+fundoplication group (18 of 60) compared with those who had only gastrostomy (12 of 82) (p=0.036). CONCLUSION: Prophylactic fundoplication may not be necessary in neurologically impaired children undergoing gastrostomy for feeding purposes. It increases the postoperative morbidity compared to gastrostomy alone in this group of children. It should be offered selectively to children continuing to have reflux-related complications after gastrostomy. The technical difficulties with a pre-existing gastrostomy can be overcome in the hands of experienced laparoscopic surgeons.


Subject(s)
Fundoplication/methods , Gastroesophageal Reflux/prevention & control , Neurodegenerative Diseases/congenital , Adolescent , Child , Child, Preschool , Endoscopy, Gastrointestinal , Enteral Nutrition/adverse effects , Enteral Nutrition/methods , Esophageal pH Monitoring , Female , Follow-Up Studies , Gastroesophageal Reflux/etiology , Gastroesophageal Reflux/surgery , Gastrostomy/adverse effects , Humans , Infant , Male , Neurodegenerative Diseases/therapy , Retrospective Studies , Time Factors , Treatment Outcome
10.
J Minim Access Surg ; 1(3): 121-8, 2005 Sep.
Article in English | MEDLINE | ID: mdl-21188009

ABSTRACT

CONTEXT: Minimal access surgery (MAS) in children are common place and performed worldwide with gratifying results as the learning curve of the surgeon attains plateau. We share our experience of this technically evolving modality of surgery, performed at our setup over a period of 5 years. We also review and individually compare the data for commonly performed procedures with other available series. Author also briefly discuss potential advantages of MAS in certain debatable conditions performed quickly and with cosmesis as open procedure. MATERIALS AND METHODS: We performed 677 MAS in children aged between 7 days and 12 years. Five hundred and sixty-eight of these were Laparoscopic procedures and 109 were Video assisted thoracoscopic surgeries (VATS). In all laparoscopic procedures, the primary port placement was by the Hasson's open technique. We have used 5, 3 and 2 mm instruments. Our study include 259 inguinal hernia, 161 Appendectomies, 95 VATS for empyema, 51 orchiopexies, 49 diagnostic laparoscopy, 29 cholecystectomies, 22 adhesionlysis and other uncommonly performed procedures. RESULTS: The ultimate outcome of all the performed procedures showed gratifying trend, the data of which are discussed in detail in the article. CONCLUSION: As we gained experience the operating time showed a decreasing trend, the complication rates and conversion rate also reduced. The advantages we came across were better postoperative appearances, less pain and early return to unrestricted activities.

12.
Ear Nose Throat J ; 79(4): 286-9, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10786392

ABSTRACT

Sublabial transsphenoidal surgical removal of pituitary tumors is a common procedure with minimal complications. Although many investigators have reported oral sensory compromises following surgery, none has reported any postoperative compromise in speaking ability. In this article, we describe the case of a 33-year-old woman who developed transient but severe speech symptoms after she underwent sublabial transsphenoidal surgery. This case prompted us to undertake a brief retrospective analysis of our experience with this procedure in other patients, which revealed that speech compromise is far more common than heretofore realized.


Subject(s)
Hypophysectomy/adverse effects , Speech Disorders/etiology , Voice Quality , Adult , Age Factors , Female , Follow-Up Studies , Humans , Hypophysectomy/methods , Male , Middle Aged , Population Surveillance , Recovery of Function , Retrospective Studies , Sex Factors , Sphenoid Sinus/surgery
13.
Med Eng Phys ; 19(4): 343-51, 1997 Jun.
Article in English | MEDLINE | ID: mdl-9302674

ABSTRACT

Pulsatile blood flow using incompressible newtonian fluid is investigated numerically in abdominal aortic aneurysm models with the aid of transient Navier-Stokes equations for axisymmetric geometry. The arterial wall is assumed to be rigid. The actual arterial pressure-velocity pulse at the abdominal aorta is used as the inlet boundary condition to the aneurysm. The corresponding velocity at every time-step is assumed to be fully developed parabolic profile at the inlet. Time-dependent formation of vortices and occurrence of stagnation zones are analyzed in this numerical study. It has been found that the distal end of the aneurysm is subjected to maximum shear stress and pressure during the entire cycle. This analysis also confirms that the mechanical forces on the arterial wall, developed by the blood flow which is pulsatile in nature, may play an important role in both development and growth of aneurysms. It has also been found that a quasi-steady state may be used to explain sufficiently the basic flow characteristic within the aneurysm. The wall shear stress in the quasi-steady state at the distal end of the aneurysm during the most adverse condition was approximately the same as in the pulsatile state for a similar situation.


Subject(s)
Aorta, Abdominal/physiopathology , Aortic Aneurysm, Abdominal/physiopathology , Pulsatile Flow , Biophysical Phenomena , Biophysics , Computer Simulation , Humans , Models, Cardiovascular
14.
J Speech Hear Res ; 38(4): 740-50, 1995 Aug.
Article in English | MEDLINE | ID: mdl-7474968

ABSTRACT

One of the core features of developmental stuttering is part-word repetition followed by fluent production (resolution) of the target word. The purpose of the study is to compare the spectro-temporal dimensions of fragments with the spectro-temporal dimensions of the resolution to define fragment types and develop articulatory interpretation of termination-restart cycles. From the acoustic recordings of six adult males who stutter, 142 stuttering events on words beginning with stops were isolated, excerpted, and digitized. The stuttering events occurred during either spontaneous speech or reading. The consecutive articulatory phases of fragments were classified and compared with the corresponding phases in resolutions. We found that (a) there are two basic types of fragments--those with vowels and those without, (b) the type of fragment produced is strongly influenced by the voicing status of the stop, (c) the fragments without vowels tend to have longer stop closure duration than the stops in the resolutions, (d) there are two subtypes in fragments with vowels--those with vowels shorter than and those with vowels longer than the vowels in the resolutions, (e) the shorter vowels differ spectro-temporally from the vowels in resolutions, and (f) the longer vowels differ temporally from the vowels in the resolutions. We discuss the articulatory implications of the acoustic data for each fragment type in the context of speech as an act designed to achieve contextually conditioned acoustic goals.


Subject(s)
Stuttering/diagnosis , Adult , Humans , Male , Middle Aged , Observer Variation , Speech Acoustics , Speech Production Measurement , Time Factors
15.
Ear Nose Throat J ; 73(12): 914, 918-20, 1994 Dec.
Article in English | MEDLINE | ID: mdl-7882883

ABSTRACT

We retrospectively evaluated three fluent asthmatic children who developed speech dysfluency following administration of theophylline. The dysfluency ceased in all three, following discontinuation of the medication. The medication was re-instituted in two patients, prompting return of dysfluency. It is unknown whether the patients had characteristics of "acquired stuttering" or "developmental stuttering." We urge appropriate testing should this complication again occur. This might then provide pharmacologic information regarding stuttering.


Subject(s)
Stuttering/chemically induced , Theophylline/adverse effects , Asthma/drug therapy , Child , Child, Preschool , Female , Humans , Male , Retrospective Studies
16.
Liver ; 14(2): 83-4, 1994 Apr.
Article in English | MEDLINE | ID: mdl-8196514

ABSTRACT

A case of diclofenac-induced hepatitis, in a 53-year-old Indian woman with recurrent jaundice, is presented. The diagnosis was suspected from the appearance of the liver biopsy and was confirmed by the temporal association with drug usage and cure on withdrawal of the drug.


Subject(s)
Chemical and Drug Induced Liver Injury/etiology , Diclofenac/adverse effects , Chemical and Drug Induced Liver Injury/diagnosis , Female , Humans , Middle Aged
17.
18.
J Assoc Physicians India ; 39(7): 529-31, 1991 Jul.
Article in English | MEDLINE | ID: mdl-1800496

ABSTRACT

One hundred patients with non ulcer dyspepsia with history of chronic tobacco chewing were examined endoscopically to assess the effect of tobacco ingestion on the gastric mucosa. Gastric erosions were seen in 20 patients in the fasting state. The remaining 80 patients in whom gastroscopy did not reveal erosions were subjected to repeat gastroscopy after tobacco ingestion. In 40 patients, endoscopy was repeated 30 minutes after 200 mg of tobacco ingestion (Group I) and in another 40 patients endoscopy was repeated 1 hour after 400 mg of tobacco ingestion (Group II). Eleven patients (27.5%) in Group I and 19 (47.5%) in Group II developed gastric erosions. Erosions were observed mainly along the lesser curvature, and in the fundus and the body of stomach. Gastric pH, determined after tobacco ingestion, was 2.4 +/- 0.43 in patients with erosions and 3.0 +/- 0.67 in patients without erosions. It is concluded that tobacco ingestion produces dose-dependent damage to the gastric mucosa as seen on endoscopy. Hence, history of tobacco ingestion should always be asked for in patients with gastric erosions.


Subject(s)
Gastric Mucosa/pathology , Gastroscopy , Plants, Toxic , Tobacco, Smokeless/adverse effects , Gastric Acidity Determination , Gastric Mucosa/drug effects , Humans , Stomach Diseases/chemically induced , Stomach Diseases/pathology
19.
J Assoc Physicians India ; 39(3): 263-4, 1991 Mar.
Article in English | MEDLINE | ID: mdl-1880096

ABSTRACT

Thirty four patients with peritoneoscopy and/or biopsy proven uncomplicated cirrhosis of liver with ascites were studied for the effect of diuretic therapy on ascitic fluid protein and cell count. Renal function tests, liver function tests, ascitic fluid protein concentration and cell count were estimated prior to diuretic therapy and once every week till the end of therapy. There was no change in mean total serum protein (5.71 +/- 0.58 g/dl to 5.72 +/- 0.63 g/dl). The rise in mean ascitic fluid protein from 1.55 +/- 0.77 g/dl to 1.76 +/- 0.79 g/dl was not significant (P greater than 0.05). Twenty one patients (Group I) showed a rise in ascitic fluid protein concentration while 13 patients (Group II) did not show a rise or showed a fall in protein concentration during diuretic therapy. The rise in ascitic fluid protein concentration in Group I from 1.62 +/- 0.69 g/dl to 2.05 +/- 0.67 g/dl was statistically significant (P less than 0.05). Group I patients had a mean weight loss of 6.21 +/- 3.66 kg as compared to 3.15 +/- 2.00 kg in Group II patients (p less than 0.05). There was no other difference between Group I and Group II patients. Only 5 patients showed a rise in ascitic fluid cell count (more than 50 cell/mm3). It is concluded that diuretic therapy alters ascitic fluid protein concentration in a majority of patients but has no significant effect on cell count.


Subject(s)
Ascitic Fluid/chemistry , Furosemide/therapeutic use , Liver Cirrhosis/drug therapy , Proteins/analysis , Spironolactone/therapeutic use , Adolescent , Adult , Aged , Aged, 80 and over , Ascitic Fluid/pathology , Blood Proteins/analysis , Cell Count , Furosemide/administration & dosage , Humans , Liver Cirrhosis/metabolism , Liver Cirrhosis/pathology , Middle Aged , Spironolactone/administration & dosage , Weight Loss
20.
J Otolaryngol ; 19(4): 231-6, 1990 Aug.
Article in English | MEDLINE | ID: mdl-2213994

ABSTRACT

We discuss the etiology of 100 spasmodic dysphonia patients. Seventy-one patients had underlying essential tremor, 25 had Meige's syndrome, 12 were hypothyroid, and 27 had either a functional disturbance or focal dystonia. Six patients had intermittent breathy dysphonia. A large corpus of spasmodic dysphonia patients have organic neurolaryngeal disease.


Subject(s)
Voice Disorders/etiology , Adolescent , Adult , Aged , Aged, 80 and over , Child , Female , Humans , Hypothyroidism/complications , Laryngoscopy , Male , Meige Syndrome/complications , Middle Aged , Retrospective Studies , Spasm/etiology , Tremor/complications , Vocal Cords/physiopathology , Voice Disorders/physiopathology
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