Synthesis, characterisation and optical spectroscopy of platinum(ii) di-ynes and poly-ynes incorporating condensed aromatic spacers in the backbone

A series of protected and terminal dialkynes with extended pi-conjugation through a condensed aromatic linker unit in the backbone, 1,4-bis(trimethylsilylethynyl)naphthalene, 1,4-bis(ethynyl)naphthalene, 9,10-bis(trimethylsilylethynyl)anthracene, 9,10-bis(ethynyl)anthracene, have been synthesized and characterized spectroscopically. The solid-state structures of and have been confirmed by single crystal X-ray diffraction studies. Reaction of two equivalents of the complex trans-[Ph(Et(3)P)(2)PtCl] with an equivalent of the terminal dialkynes 1,4-bis(ethynyl)benzene and, in (i)Pr(2)NH-CH(2)Cl(2), in the presence of CuI, at room temperature, afforded the platinum(II) di-ynes trans-[Ph(Et(3)P)(2)Pt-C[triple bond, length as m-dash]C-R-C[triple bond, length as m-dash]C-Pt(PEt(3))(2)Ph](R = benzene-1,4-diyl; naphthalene-1,4-diyl and anthracene-9,10-diyl ) while reactions between equimolar quantities of trans-[((n)Bu(3)P)(2)PtCl(2)] and under similar conditions readily afforded the platinum(II) poly-ynes trans-[-((n)Bu(3)P)(2)Pt-C[triple bond]C-R-C[triple bond]C-](n)(R = naphthalene-1,4-diyl and anthracene-9,10-diyl ). The Pt(II) diynes and poly-ynes have been characterized by analytical and spectroscopic methods, and the single crystal X-ray structures of and have been determined. These structures confirm the trans-square planar geometry at the platinum centres and the linear nature of the molecules. The di-ynes and poly-ynes are soluble in organic solvents and readily cast into thin films. Optical spectroscopic measurements reveal that the electron-rich naphthalene and anthracene spacers create strong donor-acceptor interactions between the Pt(II) centres and conjugated ligands along the rigid backbone of the organometallic polymers. Thermogravimetry shows that the di-ynes possess a somewhat higher thermal stability than the corresponding poly-ynes. Both the Pt(II) di-ynes and the poly-ynes exhibit increasing thermal stability along the series of spacers from phenylene through naphthalene to anthracene.

Socio-economic and demographic factors associated with injecting drug use among drug users in Karachi, Pakistan

OBJECTIVE

To identify the socio-economic and demographic factors associated with injecting drug users (IDUs) in Karachi.

METHODS

We recruited 242 IDUs (taking drugs through sub-dermal routes) and 231 non-IDUs (taking drugs other than sub-dermal routes) from February through June 1996. IDUs were interviewed regarding sociodemographic factors, economic condition, and social network (marital status, living with spouse). In addition, information regarding location of drug users within the city (districts of Karachi) and current history of sexually transmitted diseases (STDs) were gathered. Moreover, blood samples were also obtained for HIV testing.

RESULTS

Multivariate analysis showed that the income generation via illegal modes [AOR 1.6, 95% CI 1.0-2.6], non-sharing of income with family [AOR 1.7, 95% CI 1.1-2.7] and presence of suicidal thoughts [AOR 2.0, 95% CI 1.1-3.8] were associated with the use of drugs through injections. Further, drug users from districts West, East and Central were more likely to use drug through injection as compared to drug users from district South. The history of genital herpes was also found to be associated with injecting drug use. One IDU was found seropositive for HIV.

CONCLUSION

The high-risk behaviors, such as illegal modes of earning and presence of suicidal thoughts, among IDUs suggest that the group needs rehabilitation programme. Moreover, non-sharing of income suggest that IDUs are isolated from social network, therefore primary prevention activities with focus on improving socio-economic conditions and social networking can reduce drug use through injections. Focused interventions on target districts would be helpful in reducing IDU.

Factors affecting unsuccessful referral by the Lady Health Workers in Karachi, Pakistan

OBJECTIVE

To estimate the proportion of patient referral and to identify the factors associated with unsuccessful referral in Karachi, Pakistan.

METHODS

In a cross-sectional survey, a total of 347 patients referred to different health care facilities by the LHWs were interviewed. Data was collected using a structured questionnaire, on demographic characteristics of patients (age, sex, income etc) and potential factors (seriousness of medical condition, distance of health facility, attitude of health center staff etc) that can affect patient referral outcome.

RESULTS

An overall referral rate of 55% was found in this study. Out of a total of 347 patients interviewed, 265 (76.4%) were successful while 82 (23.6%) were unsuccessful referrals. Multivariate logistic regression analysis showed that objection to referral (Adjusted OR, 2.96; CI: 1.44-5.52), never referred before (Adjusted OR, 1.25; CI: 1.34-6.90), not visited the referral site before (Adjusted OR, 4.04; CI: 2.50-6.08) and no knowledge of who to meet at the referral site (Adjusted OR, 1.30; CI: 1.01-2.96) were the factors associated with unsuccessful referral. Other factors found significant were duration of the illness of the patient, anyone not known at the referral site and failure of LHW to follow up.

CONCLUSION

Our study found that a significant proportion of patients seen by the LHWs are referred to different health facilities. Improved management skills of LHWs for simple medical problems would probably reduce the number of referrals. Efforts should also be directed to enhance the communication and counseling skills of LHWs, which may reduce a significant proportion of unsuccessful referrals.

The energy gap law for triplet states in Pt-containing conjugated polymers and monomers

The energy gap law established for aromatic hydrocarbons and rare earth ions relates the nonradiative decay rate to the energy gap of a transition through a multiphonon emission process. We show that this energy gap law can be applied to the phosphoresce of a series of conjugated polymers and monomers for which the radiative decay rate has been enhanced through incorporation of a heavy metal. We find that the nonradiative decay rate from the triplet state T(1) increases exponentially with decreasing T(1)-S(0) gap for the polymers and monomers at 300 and 20 K. Comparison of the nonradiative decay of polymers with that of their corresponding monomers highlights the role of electron-lattice coupling.

Monostotic fibrous dysplasia of the temporal bone

Fibrous dysplasia is a rare but interesting benign condition of the bones which affects either a single bone or multiple bones, with or without endocrine abnormalities. Only 75 cases affecting the temporal bone have been reported in the world literature, and to these we add another case. Although systemic involvement in the form of endocrine abnormalities and skin pigmentation has been reported in the past, no case has yet been reported with a congenitally absent kidney in the monostotic form of the disease.

Leprosy in ENT

Two cases of leprosy are reported, one of which was admitted as a case of acute tonsillitis and was referred only later to the ENT surgeons with hoarseness after a diagnosis had been made by biopsy of the lymph node; the other was referred with a possible facial paralysis. This is a rare diagnosis but it should still be kept in mind, particularly in the immigrant population of the United Kingdom and Saudi Arabia and particularly of the Saudis from the southern provinces.

Nasal glioma and encephalocele: two separate entities. Report of two cases

The term "nasal glioma" is a confusing misnomer as it implies a neoplastic condition with malignant potential, which it is not. Nasal glioma is a rare development abnormality and should be differentiated from glioma, which is a malignant tumor of the brain, and from a primary encephalocele, which is herniation of the cranial contents through a bone defect in the skull, through which it retains an intact connection with the central nervous system. Two cases of nasal glioma, one with and one without intracranial connections, are described and the literature is reviewed.

Growth performance, immune status and organ morphometry in broilers fed Bacillus subtilis-supplemented diet

The present research aimed to investigate the effects of Bacillus subtilis (B. subtilis) on performance, immune system, gut, and lymphoid organs’ microarchitecture in broilers. A total of 120 day-old broiler chicks were randomly distributed into four groups. The birds were fed a corn-soy-based basal diet (BD) (control) or the same BD supplemented with 10% zinc bacitracin (ZnB), 0.05 g/kg or 0.1 g/kg of B. subtilis (BS). The broilers fed 0.1 g/kg of B. subtilis had superior mean bodyweight and lower feed conversion ratio compared with the non-supplemented or ZnB-fed groups. The BS-0.1 group registered higher antibody titer against the Newcastle disease (ND) virus. Cell-mediated immune response post Phytohaemagglutinin-P (PHA-P) injection was attained by both BS-0.1 and BS-0.05 groups. Histomorphological study revealed increased thymus cortical width, and cortex/medulla ratio in BS-0.1 group compared with control. Area of bursal follicles and germinal centres of spleen also improved in BS-0.1 group. Compared to ZnB and control, higher villus height (VH) and villus crypt ratio of the duodenum and jejunum were recorded on day 21, and higher VH of duodenum and ileum was noted on day 35 in BS-0.1 and BS-0.05 groups. In conclusion, B. subtilis-type probiotics contributed positively to better growth performance, improved immune system and modulated morphology of lymphoid organs and gut mucosa in broilers.Keywords: Immunity, intestinal mucosa, poultry, probiotics