Dynamic Structural Evolution and Dual Emission Behavior in Hybrid Organic Lead Bromide Perovskites

The optoelectronic properties of organic lead halide perovskites (OLHPs) strongly depend on their underlying crystal symmetry and dynamics. Here, we exploit temperature-dependent synchrotron powder X-ray diffraction and temperature-dependent photoluminescence to investigate how the subtle structural changes happening in the pure and mixed A-site cation MA1-xFAxPbBr3 (x = 0, 0.5, and 1) systems influences their optoelectronic properties. Diffraction investigations reveal a cubic structure at high temperatures and tetragonal and orthorhombic structures with octahedral distortion at low temperatures. Steady state photoluminescence and time correlated single photon counting study reveals that the dual emission behavior of these OLHPs is due to the direct-indirect band formation. In the orthorhombic phase of MAPbBr3, the indirect band is dominated by self-trapped exciton (STE) emission due to the higher-order lattice distortions of PbBr6 octahedra. Our findings provide a comprehensive explanation of the dual emission behavior of OLHPs while also providing a rationale for previous experimental observations.

Decorin production by the human decidua: role in decidual cell maturation

Decidualization involves the proliferation and differentiation of fibroblast-like endometrial stromal cells into epithelioid-shaped and secretory 'decidual' cells in response to steroid hormones. Human decidual cells produce insulin-like growth factor-binding protein-1 and prolactin (PRL), two well-recognized markers of decidual cell maturation and a proteoglycan decorin (DCN). We reported that DCN restrains the human trophoblast renewal, migration, invasion and endovascular differentiation needed for uterine arterial remodeling during normal pregnancy. DCN overproduction by the decidua is associated with a hypo-invasive placenta and a serious pregnancy disorder, pre-eclampsia (PE). Furthermore, elevated maternal plasma DCN levels during the second trimester is a predictive biomarker of PE. While these paracrine roles of decidua-derived DCN on trophoblast physiology and pathology have been well-defined, it remains unknown whether DCN plays any autocrine role in decidual cell development. The objectives of this study were to examine: the kinetics of DCN production during decidualization of human endometrial stromal cells; gestational age-related changes in DCN production by the first trimester decidua; and a possible autocrine role of DCN on decidual cell maturation. We found that DCN production is enhanced during decidualization of both primary and immortalized human endometrial stromal cells in vitro and during early gestation in decidual samples tested ex vivo, and that it is important for endometrial stromal cell maturation into a decidual phenotype. Decorin-depleted human endometrial stromal cells exposed to decidualizing stimuli failed to mature fully, as evidenced by fibroblastoid morphology, reduced insulin-like growth factor-binding protein-1 and PRL expression, and reduction in cellular ploidy. We identified heart and neural crest derivatives-expressed protein 2, and progesterone receptor as potential downstream mediators of DCN effects.

Dynamic structural property of organic-inorganic metal halide perovskite

Unique organic-inorganic hybrid semiconducting materials have made a remarkable breakthrough in new class of photovoltaics (PVs). Organic-inorganic metal (Pb and/or Sn) halides (-I, -Br, and -Cl) are the semiconducting absorber with the crystal structure of the famous "Perovskite". It is widely called "perovskite solar cells (PSCs)" in PV society. Now, the power conversion efficiency (PCE) of PSCs is recorded in 25.5%. Prototypical composition of the absorbers is (A = methylammonium [MA], formamidinium [FA], and Cs), (M = Pb and/or Sn), and (X = I, Br, and Cl) in the form of perovskite AMX₃. Since the report on the stable all solid-state PSCs in 2012, the average annual growth rate of PCE is well over ∼10%. Such an outstanding PV performance attracts huge number of scientists in our research society. Their chemical as well as physical properties are dramatically different from monocrystalline Si, GaAs, other III-IV semiconductors, and many oxides with the crystal structure of perovskite. In this review, different fundamental aspects, in particular, the dynamic properties of A site cationic molecules and PbI₆ octahedrons linked with their corners, from other semiconducting and dielectric materials are reviewed and summarized. Upon discussing unique properties, perspectives on the promising PV applications based on the comprehension in dynamic nature of the orientation in A site molecule and PbI₆ octahedron tilting will be given.

Probing the Electronic Structure of Hybrid Perovskites in the Orientationally Disordered Cubic Phase

Hybrid organic-inorganic lead halide perovskites are projected as new generation photovoltaic and optoelectronic materials with improved efficiencies. However, their electronic structure so far remains poorly understood, particularly in the orientationally disordered cubic phase. We performed electronic structure investigations using angle-resolved photoemission spectroscopy on two prototypical samples (MAPbBr₃ and MAPbCl₃) in their cubic phase, and the results are compared with the calculations within two theoretical models where MA⁺ is orientationally (1) disordered (MA⁺ ion is replaced by spherically symmetric Cs⁺ ion) and (2) ordered (MA oriented along (100) direction) but keeping the symmetry of the unit cell cubic. Degeneracy of the valence bands and behavior of constant energy contours are consistent with model 1, which supports strongly the disordered nature of the orientation of the MA⁺ ions in the cubic phase. Band structure calculations also reveal that spin-orbit coupling induced Rashba splitting is suppressed by the orientational disorder.

Role of alkali charge compensation in the luminescence of CaWO4:Nd3+ and SrWO4:Nd3+ Scheelites

The present work demonstrates the distinct role of alkali metal ion charge compensators on the luminescence of NIR-emitting Nd³⁺ Scheelite. The unit cell dimensions of the host lattice and excitation wavelength play a very important role.

Coenzyme Q10 ameliorates cadmium induced reproductive toxicity in male rats

This study aimed at investigating the protective role of CoQ10 against cadmium (Cd)-induced reproductive toxicity in male rats. Adult male Wistar rats were exposed to an acute dose of Cd (25 mg/kg bwt; Cd group), Cd+CoQ10 (25 mg/kg bwt Cd+10 mg CoQ10; Cd-Q10 group) and distilled water (control) in vivo for 15 consecutive days and semen quality was assessed. A significant reduction was noted in sperm concentration, progressive motility, morphology and DNA integrity in both Cd- and Cd-Q10 groups in comparison to control indicating Cd-induced testicular lipid per oxidation (LPO) and decline in indigenous antioxidant defense system as measured by total antioxidant capacity (TAC) (p<0.05). However, simultaneous co-administration of CoQ10 along with Cd (Cd-Q10 group) was able to improve sperm concentration, motility, progressive motility, morphology, DNA integrity, and testicular TAC as well as lower LPO compared to Cd group (p<0.05). Results indicate that used dose of CoQ10 is capable of moderately ameliorating reproductive toxicity of Cd by improving semen quality and reducing testicular oxidative stress.

Room temperature growth of CH3NH3PbCl3 single crystals by solvent evaporation method

Rectangular shaped, high crystalline quality, defect free and colorless 3D perovskite single crystals of CH₃NH₃PbCl₃ were grown using the solvent evaporation method at room temperature for the first time.

Self-immobilized Pd nanowires as an excellent platform for a continuous flow reactor: efficiency, stability and regeneration

Despite extensive use of Pd nanocrystals as catalysts, the realization of a Pd-based continuous flow reactor remains a challenge. Difficulties arise due to ill-defined anchoring of the nanocrystals on a substrate and reactivity of the substrate under different reaction conditions. We demonstrate the first metal (Pd) nanowire-based catalytic flow reactor that can be used across different filtration platforms, wherein, reactants flow through a porous network of nanowires (10-1000 nm pore sizes) and the product can be collected as filtrate. Controlling the growth parameters and obtaining high aspect ratio of the nanowires (diameter = ∼13 nm and length > 8000 nm) is necessary for successful fabrication of this flow reactor. The reactor performance is similar to a conventional reactor, but without requiring energy-expensive mechanical stirring. Synchrotron-based EXAFS studies were used to examine the catalyst microstructure and Operando FT-IR spectroscopic studies were used to devise a regenerative strategy. We show that after prolonged use, the catalyst performance can be regenerated up to 99% by a simple wash-off process without disturbing the catalyst bed. Thus, collection, regeneration and redispersion processes of the catalyst in conventional industrial reactors can be avoided. Another important advantage is avoiding specific catalyst-anchoring substrates, which are not only expensive, but also non-universal in nature.

CH3NH3PbI3, A Potential Solar Cell Candidate: Structural and Spectroscopic Investigations

Hybrid organic-inorganic metal halides of the type CH₃NH₃PbX₃ have emerged as potential materials for photovoltaic applications. In this paper we discuss structural, electronic, and optical spectroscopy investigations performed on high quality single crystals of CH₃NH₃PbI₃. Our results conclusively suggest that CH₃NH₃PbI₃ crystallizes in centrosymmetric space group and the methylammonium moiety exhibits disordered packing at room temperature. Extracted values of the exciton binding energy, the electron-phonon coupling constant, and the schematic energy level diagram constructed from the emission broadening, Raman, and photoemission spectroscopy measurements clearly show the potential of this system in photovoltaic applications.

Riboflavin conjugated temperature variant ZnO nanoparticles with potential medicinal application in jaundice

Significant ameliorative efficiency of riboflavin conjugated ZnO nanoparticles against jaundice stress at molecular and cellular levels.

Prevalence and Covariates of Undiagnosed Hypertension in the Adult Population of Puducherry, South India

Background Globally the prevalence of both hypertension and pre-hypertension are increasing and pre-hypertension has been associated with higher cardiovascular risk. The objective of this study was to find out the prevalence of undiagnosed hypertension and pre-hypertension and associated covariates among adults of rural and urban area of Puducherry. Material and Methods A population based cross-sectional study was carried out in the field practices area of Department of Community Medicine, Mahatma Gandhi Medical College and Research Institute without intervention. Results Among 856 participants, 27.6 percent were hypertensive and 57 percent pre-hypertensive; the magnitude of both stage 1 and stage 2 hypertension increased with the age. Of the hypertensives, 26.3 and 28.7 percent were from rural and urban area respectively, whereas in pre-hypertension the corresponding figures were 61 and 53.4 percent.  Significantly increased risk of hypertension was noted among adults with increasing age, having less than six members in the family, suffering from obesity (general and abdominal obesity) and living sedentary life. On the other hand, the probability of having increased risk of pre-hypertension was significantly higher among adults living in the rural areas, having non-vegetarian dietary habit, suffering from obesity (general and abdominal obesity), living sedentary life and having family history of hypertension. Multivariate logistic regression however showed significant correlation of hypertension with increasing age, sedentary lifestyle, tobacco addiction and obesity (general and central). Significant correlates of pre-hypertensive were rural residence, sedentary living habits, family history of hypertension, tobacco addiction and obesity (general and central). Conclusion The present findings show high prevalence of hypertension and pre-hypertension among population of Puducherry in South India.DOI: http://dx.doi.org/10.3126/nje.v2i2.6576 Nepal Journal of Epidemiology 2012;2(2):191-199

Intervention to increase detection of childhood tuberculosis in Bangladesh

BACKGROUND

Despite a well-functioning adult tuberculosis (TB) control programme, children with TB remain grossly under-detected in Bangladesh. It is conservatively estimated that annually around 21,000 children with TB go undetected, due to an almost exclusive focus on sputum smear-positive TB and the absence of training or guidelines in paediatric TB.

OBJECTIVE

To double child TB detection by increasing general awareness and training of health care workers at microscopy centres supported by the Damien Foundation (DF) Bangladesh.

METHODS

A cluster-randomised trial was carried out with provision of child TB guidelines, training and logistics support to staff of 18 microscopy centres, while 18 non-adjacent microscopy centres continued their usual practice and served as controls. Paediatric data on TB suspect referral and case detection were collected at baseline and during the intervention at both control and intervention sites.

RESULTS

Child TB case detection increased in both intervention and control microscopy centres, but the increase was three times the baseline in the intervention centres (from 3.8% to 12%) in comparison to less than double the baseline in the control centres (from 4.3% to 7%, P = 0.001).

CONCLUSION

Simple guidelines and training on child TB case detection, together with basic logistics support, can be integrated into the existing National TB Control Programme and improve service delivery to children in TB-endemic areas.

Methylene blue is a good background stain for tuberculosis light-emitting diode fluorescence microscopy

SETTING

Damien Foundation Bangladesh tuberculosis (TB) control projects.

OBJECTIVES

To compare blue ink, potassium permanganate and methylene blue background staining for transmitted light-emitting diode (LED) TB fluorescence microscopy (FM).

DESIGN

Auramine smears made in triplicate from Ziehl-Neelsen (ZN) acid-fast bacilli (AFB) positive or negative sputum and stained with one of the background variations were read blind by LED FM. Reference laboratory rechecking of discordant series was used before and after auramine restaining as the gold standard.

RESULTS

Of 1977 series evaluated, 991 (50.1%) were made from ZN-positive specimens. There were 919, 942 and 958 FM true-positives with blue ink, permanganate and methylene blue counterstaining, against respectively 12, 12 and 16 false-positives. Methylene blue counterstaining was more sensitive (95.6%, 95%CI 94.2-96.8) than blue ink or permanganate (92.7%, 95%CI 90.9-94.3 and 93.6%, 95%CI 91.9-95.0; respectively P < 0.01 and < 0.05). No AFB could be found in 85% and 18% of 180 discordant series without and with restaining.

CONCLUSIONS

Methylene blue is at least equivalent to potassium permanganate counterstaining for FM using blue LED transmitted excitation and is cheaper than blue ink. Restaining of all smears prior to first re-reading may be unavoidable for blinded rechecking of auramine-stained smears for external quality assessment.

Femtosecond laser written channel waveguides in tellurite glass

We have made and characterized a new, erbium-doped tellurite glass that has high glass transition temperature. Addition of phosphate is found to increase the phonon energy. The peak emission cross section is 6 x 10(-21) cm(2) at 1537 nm and the fluorescence lifetime of the (4)I(13/2)-(4)I(15/2) transition is 4.1 ms. We have written 2-D channel waveguides in this glass using focused, 45-fs pulses from an amplified Ti:sapphire laser at different laser energies and writing speeds. Migration of atoms towards the periphery of the waveguides occurs, leading to refractive index changes. Channels show waveguiding at 1310 nm which is promising for the fabrication of integrated lasers and broadband amplifiers.

Managing severe lower limb spasticity in multiple sclerosis: does intrathecal phenol have a role?

OBJECTIVE

Established treatment options for managing severe lower limb spasticity and associated pain are of limited value in people with advanced multiple sclerosis (MS). This has resulted in a resurgence of the use of lumbar intrathecal phenol injection (IP). The aim of this study was to investigate the authors' experience with IP.

METHODS

This observational study collected cross sectional data from patients with progressive MS who received IP for severe lower limb spasticity. Data from 25 patients were collected prospectively before and after treatment. In 15 cases the data related to the first treatment and in 10 to serial injections. Outcome measures collected included the Ashworth scale, a spasm frequency scale, a pain rating score, and the percentage achievement of practical goals.

RESULTS

After injection, all patients demonstrated reduced lower limb tone bilaterally. After the initial injection there was significant improvement on the targeted as compared with the non-targeted side (Wilcoxon rank p=0.003), while no difference in the degree of improvement between the targeted and non-targeted side was seen after serial injections (Wilcoxon rank p=0.731). Twenty four patients were easier to position and 21 had a reduction in their spasm frequency and intensity. Eleven patients with pain reported benefit. Carers found washing and dressing easier in 16 patients and improved safety when using the hoist in 10. Six patients had recurrence of skin breakdown and five patients reported transient adverse changes in their bowel function.

CONCLUSIONS

IP can reduce lower limb tone bilaterally after both initial and serial injections. This is most noticeable on the targeted side after initial injection. IP can reduce spasms and pain, leading to improvements in care and overall comfort. IP is an effective treatment option in the management of severe spasticity. Documented selection criteria are essential.

The prion protein has RNA binding and chaperoning properties characteristic of nucleocapsid protein NCP7 of HIV-1

Transmissible spongiform encephalopathies are fatal neurodegenerative diseases associated with the accumulation of a protease-resistant form of the prion protein (PrP). Although PrP is conserved in vertebrates, its function remains to be identified. In vitro PrP binds large nucleic acids causing the formation of nucleoprotein complexes resembling human immunodeficiency virus type 1 (HIV-1) nucleocapsid-RNA complexes and in vivo MuLV replication accelerates the scrapie infectious process, suggesting possible interactions between retroviruses and PrP. Retroviruses, including HIV-1 encode a major nucleic acid binding protein (NC protein) found within the virus where 2000 NC protein molecules coat the dimeric genome. NC is required in virus assembly and infection to chaperone RNA dimerization and packaging and in proviral DNA synthesis by reverse transcriptase (RT). In HIV-1, 5'-leader RNA/NC interactions appear to control these viral processes. This prompted us to compare and contrast the interactions of human and ovine PrP and HIV-1 NCp7 with HIV-1 5'-leader RNA. Results show that PrP has properties characteristic of NCp7 with respect to viral RNA dimerization and proviral DNA synthesis by RT. The NC-like properties of huPrP map to the N-terminal region of huPrP. Interestingly, PrP localizes in the membrane and cytoplasm of PrP-expressing cells. These findings suggest that PrP is a multifunctional protein possibly participating in nucleic acid metabolism.

The prion protein has DNA strand transfer properties similar to retroviral nucleocapsid protein

The transmissible spongiform encephalopathies are fatal neurodegenerative diseases that are associated with the accumulation of a protease-resistant form of the cellular prion protein (PrP). Although PrP is highly conserved and widely expressed in vertebrates, its function remains a matter of speculation. Indeed PrP null mice develop normally and are healthy. Recent results show that PrP binds to nucleic acids in vitro and is found associated with retroviral particles. Furthermore, in mice the scrapie infectious process appears to be accelerated by MuLV replication. These observations prompted us to further investigate the interaction between PrP and nucleic acids, and compare it with that of the retroviral nucleocapsid protein (NC). As the major nucleic acid-binding protein of the retroviral particle, NC protein is tightly associated with the genomic RNA in the virion nucleocapsid, where it chaperones proviral DNA synthesis by reverse transcriptase. Our results show that the human prion protein (huPrP) functionally resembles NCp7 of HIV-1. Both proteins form large nucleoprotein complexes upon binding to DNA. They accelerate the hybridization of complementary DNA strands and chaperone viral DNA synthesis during the minus and plus DNA strand transfers necessary to generate the long terminal repeats. The DNA-binding and strand transfer properties of huPrP appear to map to the N-terminal fragment comprising residues 23 to 144, whereas the C-terminal domain is inactive. These findings suggest that PrP could be involved in nucleic acid metabolism in vivo.

Dietary chemoprevention of clastogenic effects of 3,4-benzo(a)pyrene by Emblica officinalis Gaertn. fruit extract

Dietary supplementation with extract of fruit of Emblica officinalis Gaertn. (a rich source of vitamin C) to mice in vivo significantly reduced the cytotoxic effects of a known carcinogen, 3,4-benzo(a)pyrene. Age-matched Swiss albino mice were fed by gavaging the fruit extract daily for 28 days. From day 9, one dose of the carcinogen was given on alternate days up to a total of eight doses. On day 29, all mice were transferred to normal diet. Control sets received the extract alone, the carcinogen alone and olive oil alone. All mice were sacrificed at 12 weeks and 14 weeks after the end of the experiment. Chromosome preparations were made from bone marrow after the usual colchicine-hypotonic-fixative-air drying-Giemsa staining schedule. Cytogenetic end points screened were the frequencies of chromosomal aberrations and of damaged cells induced. The cytotoxic effects were significantly lower in the mice given the fruit extract with the carcinogen than in those given the carcinogen alone.

Prediction of rib fracture injury outcome by an artificial neural network

Outcome-based therapy is becoming the standard for assessing patient care efficacy. This study examines the ability of an artificial neural network to predict rib fracture injury outcome based on 20 intake variables determined within 1 hour of admission. The data base contained 580 patient records with four outcome variables: Length of hospital stay (LOS), ICU days, Lived, and Died. A 522-patient training set and a 58-patient test set were randomly selected. Nine networks were set up in a feed-forward, back-propagating design with each trained under different initial conditions. These networks predicted the test set outcome variables with an accuracy as high as 98% at the 80% testing level. Internal weight matrix examination indicated that age, ventilatory support, and high trauma scores were strongly associated with both ICU days and mortality. Being female, injury severity, and injury type were associated with increased LOS. Smoking and rib fracture number were low-level predictors of the four outcome variables.

The Sparklet carbon dioxide resuscitator

The use of carbon dioxide in resuscitation was advocated in the 1920s and 1930s. A device, the Sparklet Resuscitator, was marketed to allow the administration of carbon dioxide gas. This piece of equipment is described and the indications for its use in resuscitation reviewed. The use of carbon dioxide appeared to have a degree of support and success as a 'universal' aid to resuscitation.

Thermogenesis after surgery: effect of perioperative heat conservation and epidural anesthesia

Body temperature, respiratory gas exchange, and plasma catecholamines were determined before and after surgery in three groups [control (C), warmed (W), and epidural (E) who received local anesthetic at T4-S5 dermatomes during and for 24 h after surgery] of patients undergoing colonic surgery under general anesthesia. At the end of surgery, group W were nursed in an ambient temperature of 28-30 degrees C, whereas the others were at 20-23 degrees C for a period of 24 h. Core (Tc) and dorsal hand temperature decreased during surgery in both C and E (P less than 0.05) but not in W. After surgery, Tc increased similarly in C and E and by a smaller amount in W. Plasma catecholamine concentrations increased significantly in C and W but not in E (P less than 0.001), with the greatest response occurring in C. Postoperative oxygen consumption and carbon dioxide production exceeded preoperative values (P less than 0.01) in C but not in W or E. After surgery, plasma albumin fell and C-reactive protein increased similarly in all three groups. Thus body heat conservation or epidural blockade attenuates or abolishes the rise in plasma catecholamines and oxygen consumption postoperatively but does not prevent the increase in Tc or the acute phase protein response.

Bovine rotavirus segment 5 protein expressed in the baculovirus system interacts with zinc and RNA

The cDNA sequence of genomic segment 5 of bovine rotavirus (RF strain) has been inserted into baculovirus transfer vectors, downstream of the polyhedrin promotor. Recombinant baculoviruses containing gene 5 were selected and the protein was expressed to high yields in Spodoptera frugiperda cells. The recombinant protein was inoculated into rabbits and mice to produce specific hyperimmune antisera. The polyclonal antiserum reacted with a protein in rotavirus-infected MA104 cells and with a protein translated in vitro. This serum was also used to confirm that the gene 5 protein is not a structural protein. Recently, the gene 5 product has been predicted to be a zinc finger protein and reported to contain a highly conserved arrangement of cysteine residues; here, we demonstrate that the recombinant gene 5 protein binds zinc and is an RNA-binding protein as are several other zinc finger proteins.

Interaction of rotavirus particles with liposomes

We have studied the interactions of purified viral particles with liposomes as a model to understand the mechanism of entry of rotavirus into the cell. Liposomes, made from pure as well as mixed lipids, that contained encapsulated self-quenching concentrations of the fluorophore carboxyfluorescein (CF) were used. Rotavirus-liposome interactions were studied from the fluorescence dequenching of CF resulting from its release to the bulk solution. Purified infectious double-shelled virus particles induced a concentration- and temperature-dependent release of CF. The rate and extent of CF release was maximum between pH 7.3 and 7.6. The removal of outer structural proteins VP4 and VP7 from virus, which results in the formation of single-shelled particles, prevented virus interaction with liposomes. Rotavirus particles with uncleaved VP4 did not interact with liposomes, but treatment in situ of these particles with trypsin restored the interaction with the liposomes and resulted in CF dequenching. Our data support the view that rotavirus enters the cell through direct penetration of the plasma membrane. In contrast, adenovirus, the only other nonenveloped virus studied by this method, shows the optimum rate of marker release from liposomes at around pH 6 (R. Blumenthal, P. S. Seth, M. C. Willingham, and I. Pastan, Biochemistry 25:2231-2237, 1986). The interaction between rotavirus and liposomes is sensitive to specific divalent metal ions, unlike the adenovirus-liposome interaction, which is independent of them.

Is hysteria on the wane? A community survey in West Bengal, India

A field survey was conducted in two villages--Gambhirgachi and Paharpur--in 1972. The survey was repeated after 10 years in the former village and after 15 years in the latter one. The second survey showed very little change in the rate of total mental morbidity. The rate of prevalence of hysteria declined significantly in both villages. In Gambhirgachi the rate of hysteria dropped from 16.9 to 4.6 per 1000 in 10 years, and in Paharpur it dropped from 32.3 to 2.05 per 1000 in 15 years.

Diffusion properties of clathrin on the surface of isolated mouse liver nuclei by the fluorescence recovery after photobleaching technique

Clathrin labeled with eosin maleimide showed physicochemical properties similar to the native clathrin. The diffusion coefficients of clathrin protomers and cages measured at 20 degrees C by the fluorescence recovery after photobleaching technique (FRAP) were found equal to (9 +/- 1).10(-8) cm2.s-1 and (3 +/- 0.4.10(-8) cm2.s-1, respectively. After incubation with isolated mouse liver nuclei suspended in an aqueous buffer, FRAP measurements showed that 78% of clathrin was immobilized on the nuclear surface. This immobile fraction might correspond to aggregates of molecules resembling coated pits. The mobile fraction had a diffusion coefficient of 2.5.10(-9) cm2.s-1 which was reduced seven times when the suspension medium of the nuclei contained 50% sucrose, showing that the aqueous phase exerted an important drag on the clathrin molecules motion diffusing on the nuclear surface.

Contagious hysteria in a West Bengal village

This article reports on the phenomenon of contagious hysteria in a village in West Bengal. The psychosocial and psychodynamic aspects are discussed.

Early intracardiac repair of large ventricular septal defects with conventional cardiopulmonary bypass and moderate hypothermia

With the use of conventional cardiopulmonary bypass and moderate hypothermia, primary intracardiac repair of large ventricular septal defects was performed in 30 children below the age of two years. All babies were falling to thrive and suffered from cardiac failure resistant to medical therapy, or had evidence of early pulmonary vascular disease. Two patients died after the operation, giving an operative mortality of 6.7%. Twenty-eight survivors have been followed for periods of one month to two and a half years. All are thriving and have normal or mildly enlarged hearts on their chest skiagrams. Primary intracardiac repair of large ventricular septal defects can be performed in infants and small children with a low operative risk when the standard cardiopulmonary bypass technique is being used.

Recurrent spontaneous pneumothorax; an effective method of talc poudrage

Between January 1977 and December 1978, 24 patients with recurrent or chronic spontaneous pneumothorax were treated in the Hong Kong University Cardiothoracic Centre at Grantham Hospital by talc pleurodesis. Talc poudrage had been carried out under local infiltration anesthesia by a technique that utilizes the Venturi principle and the help of an oxygen injector, used normally for ventilating a patient during bronchoscopy with a rigid bronchoscope. By using this method of poudrage, a uniform application of the powder over the whole pleural surface can be achieved and successful pleurodesis can be obtained in all patients under local anesthesia.

Incidence of postoperative deep vein thrombosis in Hong Kong Chinese

Postoperative deep vein thrombosis is considered to be rare in Chinese. The 125I-labelled fibrinogen test was used to determine the true incidence of postoperative deep vein thrombosis in Chinese. Deep vein thrombosis was found in 2.6 per cent, a very low incidence compared with Caucasian series.

Lipothymoma

Two cases of asymptomatic lipothymoma, discovered on "routine" roentgenograms of the chest, are presented. Thirty well-documented reports of this tumor in the English literature are reviewed. The pertinent points concerning this rare clinicopathological entity are summarized and discussed.

Y incision for median sternotomy

Between July 1968 and June 1977, in the University of Hong Kong Department of Surgery, 1,083 patients underwent operations via a median sternotomy using a Y incision. Of these patients, 1,070 had open heart surgery, eight had total thymectomy and in five patients pericardectomy was carried out. The overall wound complication rate was 2.31%, with a wound infection rate of 1.24%. The main advantage of a Y incision is that it leaves a better cosmetic appearance than the usual vertical incision because the upper end of the scar is at a much lower level. The incidence of subcutaneous haematoma and subsequent wound infection is much lower with the Y incision, whereas the T incision is associated with a high rate of both these complications due to the large upper flap that one has to create and mobilize to expose the suprasternal area. While using the Y incision, one only requires a small V-shaped upper flap to obtain access to the suprasternal space.

Coexistent bronchogenic carcinoma and active pulmonary tuberculosis

Sixty-four cases of coexistent bronchogenic carcinoma and active pulmonary tuberculosis were diagnosed between 1969 and 1976. The majority were male chronic cigarette smokers in their fifth and sixth decades. Human bacilli were isolated in 48 patients (88.9 percent) and atypical bacilli in six patients (11.1 percent). All of the atypical bacilli and 8.3 percent of the human bacilli were found to be resistant to the first line antituberculous drugs. All patients, except two who died following resection, were given a course of antituberculous drugs with 93.8 percent successful sputum conversion. Uncontrolled or disseminated tuberculous infection was not observed. Forty-five patients (70.3 percent) underwent pulmonary resection. Median survival time of those who had curative resection was 14.3 months with a 5 year survival rate of 13.2 percent. Median survival times of those treated by palliative resection plus anticancer chemotherapy and by anticancer chemotherapy alone were 8.3 months and 11.1 months, respectively. None of these patients survived more than 30 months. It appears that, clinically, each disease runs its own course with little effect on the other.

Foreign body in the oesophagus: review of 2394 cases

A total of 2394 patients with a foreign body in the oesophagus was treated in our unit between 1965 and 1976, including 343 children in whom fish bones (146) and coins (134) were most commonly responsible; in adults, bones (fish and chicken) were commonest. Most of the foreign bodies were impacted in the cervical oesophagus. Pharyngoscopy and oesophagoscopy were carried out under general anaesthesia in all cases except those in which the foreign body was ejected spontaneously or when the patient refused the examination. Oesophageal perforation due to a foreign body was encountered in only one child. Two patients in the series developed the fearsome complication of oesophagoaortic fistula.

An unusual lethal complication associated with Starr-Edwards prosthetic aortic valve holder

This is the first report of an unusual fatal complication associated with the Starr-Edwards prosthetic aortic valve holder. The patient died 51 days after replacement of his aortic valve with a Starr-Edwards prosthetic aortic valve. The cause of death was coronary arterial embolus caused by a fragment broken off of the prosthetic aortic valve holder.

Surgery of isolated patent ductus arteriosus: a new technique of suture and division

Since mid-1973 29 cases of isolated patent ductus arteriosus were treated in the Hong Kong University surgical unit with a new technique of suture and division. This technique has almost eliminated the problem of intraoperative haemorrhage and its consequences.

Mediastinoscopy in the diagnosis of thoracic disease

One hundred and forty-one patients have undergone mediastinoscopy in the Hong Kong University Surgical Unit since March 1974. Among these there were 109 cases of bronchogenic carcinoma. In approximately 50% of these patients the carcinoma had already spreed to involve the mediastinal lymph nodes at the time of examination. Mediastinoscopy may be the only source of positive histological proof of the diagnosis in bronchogenic carcinoma as well as in other types of intrathoracic disease such as tuberculosis. We believe that mediastinoscopy reduces the number of unnecessary exploratory thoracotomies.

Closure of pericardium after open heart surgery. A way to prevent postoperative cardiac tamponade

Between July 1968 and December 1975, 821 patients underwent open heart operations. In 596 cases the pericardium was left open and in 225 the pericardium was closed. Forty-one patients in the open pericardium group required reoperation and 23 of these had tamponade. Four patients in the closed pericardium group had reoperation but there was not a single case of tamponade. In most cases that required reoperation the bleeding was from extrapericardial sources. Absence of tamponade in the closed pericardium group can be explained by the fact that blood from extrapericardial sources of bleeding cannot collect round the heart because the pericardium is closed. Thus closure of pericardium helps to prevent tamponade. Reoperations some months or years after the original operation are technically easier and less hazardous if the pericardium has been closed because the closed pericardium prevents the heart from becoming adherent to the back of sternum and also because there are fewer adhesions in the pericardial cavity.