Low-dimensional behavior of Kuramoto model with inertia in complex networks.

Low-dimensional behavior of large systems of globally coupled oscillators has been intensively investigated since the introduction of the Ott-Antonsen ansatz. In this report, we generalize the Ott-Antonsen ansatz to second-order Kuramoto models in complex networks. With an additional inertia term, we find a low-dimensional behavior similar to the first-order Kuramoto model, derive a self-consistent equation and seek the time-dependent derivation of the order parameter. Numerical simulations are also conducted to verify our analytical results.

Analysis of cluster explosive synchronization in complex networks.

Correlations between intrinsic dynamics and local topology have become a new trend in the study of synchronization in complex networks. In this paper, we investigate the influence of topology on the dynamics of networks made up of second-order Kuramoto oscillators. In particular, based on mean-field calculations, we provide a detailed investigation of cluster explosive synchronization (CES) [Phys. Rev. Lett. 110, 218701 (2013)] in scale-free networks as a function of several topological properties. Moreover, we investigate the robustness of discontinuous transitions by including an additional quenched disorder, and we show that the phase coherence decreases with increasing strength of the quenched disorder. These results complement the previous findings regarding CES and also fundamentally deepen the understanding of the interplay between topology and dynamics under the constraint of correlating natural frequencies and local structure.

Design, synthesis and docking studies of quinoline-oxazolidinone hybrid molecules and their antitubercular properties.

New series of quinoline-oxazolidinone hybrid molecules were synthesized based on the preliminary docking studies. All the newly synthesized compounds were characterized by spectral analyses. The newly synthesized compounds were screened for their antimycobacterial properties based on the promising preliminary antibacterial screening results. Amongst tested compounds, compounds 8a, 8j and 13a were active at 0.65 µg/mL against Mycobacterium tuberculosis H(37)Rv strain. The mode of action of these active compounds was carried out by docking of receptor enoyl-ACP reductase with newly synthesized candidate ligands 8a, 8j and 13a. These compounds exhibited well established bonds with one or more amino acids in the receptor active pocket. From the docking studies, compound 8j was considered to be the best inhibitor.

Design, synthesis and docking studies of new quinoline-3-carbohydrazide derivatives as antitubercular agents.

Three new series of 4-hydroxy-8-trifluoromethyl-quinoline derivatives were synthesized through multi step reactions. All the newly synthesized compounds were characterized by spectral and elemental analyses. The structure of 5j was evidenced by X-ray crystallographic study. The newly synthesized title compounds were evaluated for their antimicrobial activities including antimycobacterial activity. Amongst the tested compounds, 5b, 5e, 5h, 5j, 6c and 7c displayed promising antimicrobial activity. The mode of action of these active compounds was carried out by docking of receptor enoyl-ACP reductase with newly synthesized candidate ligands, 5b, 5e, 5h, 5j and 6c.

New quinolin-4-yl-1,2,3-triazoles carrying amides, sulphonamides and amidopiperazines as potential antitubercular agents.

Three new series of quinoline-4-yl-1,2,3-triazoles carrying amides, sulphonamides and amidopiperazines were synthesized through multi-step reactions. The required intermediate, [1-(6-methoxy-2-methylquinolin-4-yl)-1H-1,2,3-triazol-4-yl]methanol (2) was prepared by treating 4-azido-6-methoxy-2-methylquinoline (1) with propargyl alcohol. Three different series of compounds were synthesized from this intermediate. All the newly synthesized compounds were characterized by spectral and elemental analyses. The structure of 2 was confirmed by X-ray crystallographic study. Further, the title compounds were evaluated for their in vitro anti-bacterial activity against five different bacterial strains and antimycobacterial activity against Mycobacterium tuberculosis H37Rv, Mycobacterium smegmatis (ATCC 19420) and Mycobacterium fortuitum (ATCC 19542). Title compounds, 6a, 6d, 6i, 6j, 7e, 10a and 10i were found to be active against Mycobacterium tuberculosis H37Rv strain and could be lead molecules of interest.

Design, synthesis and antimicrobial activities of some new quinoline derivatives carrying 1,2,3-triazole moiety.

A new series of [1-(6-methoxy-2-methylquinolin-4-yl)-1H-1,2,3-triazol-4-yl] methanamine derivatives were synthesized starting from 4-methoxyaniline through multi-step reactions. The title compounds 5a-y were prepared by treating the azide intermediate 4 with propargyl bromide and different alkyl/heterocyclic amines in a sequential three component synthesis. All the new compounds were characterized by spectral and elemental analyses. The newly synthesized final compounds were evaluated for their in vitro antibacterial and antifungal activities against pathogenic strains. The preliminary screening results indicated that most of the compounds demonstrated moderate to very good antibacterial and antifungal activities, comparable to the first-line drugs.

New quinoline derivatives: synthesis and investigation of antibacterial and antituberculosis properties.

Four new series of quinoline derivatives were synthesized starting from 2-trifluoromethyl aniline through multi-step reactions. In the reaction sequence, substituted aniline was cyclized to 4-hydroxy quinoline 1, which was then transformed to 4-chloro-2,8-bis(trifluoromethyl)quinoline 2. The key scaffold 4-hydrazinyl-2,8-bis(trifluoromethyl)quinoline 3, obtained from the compound 2, was successfully converted to target quinoline derivatives, viz. hydrazones 4a-t, ureas 5a-e, thioureas 6a-c and pyrazoles 7a-d, in good yields. The newly synthesized title compounds were evaluated for their in vitro antibacterial activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Klebsiella pneumoniae (recultured) and antituberculosis activity against Mycobacterium tuberculosis H(37)Rv and MDR-TB. Preliminary results indicated that most of the hydrazone derivatives demonstrated very good antibacterial and antituberculosis activities while other derivatives showed moderate activity.

Health status of 'Ruhr-City' in 2025--predicted disease burden for the metropolitan Ruhr area in North Rhine-Westphalia.

BACKGROUND: Demographic change is a driving force of disease burden. The German population is aging and simultaneously shrinking, due to a rising life expectancy and a declining fertility rate. North Rhine-Westphalia (NRW) is the most populous federal state of Germany including the Ruhr metropolitan area. The NRW population is expected to shrink by 2.5% until 2025, the population of the Ruhr area by 9.5%. At the same time, the population forecast predicts a growth of 30% in the age group > or =55 years for NRW. METHODS: The 'burden of disease' approach of the World Health Organisation (WHO) summarizes the health status of populations. This approach was used to predict the regional disease burden in 2025 by calculating disability adjusted life years (DALY) as the sum of life years lost due to premature death and years lived with disability due to selected diseases. Our projection included selected tumours, myocardial infarction (MI) and dementia. RESULTS: For the Ruhr area, increases in DALYs are expected for all causes studied, i.e. selected tumours (20%), MI (17%) and dementia (36%). The increase in the Ruhr area was estimated to be proportionally lower than in NRW in total, but the disease burden per inhabitant is higher. CONCLUSION: The population shrinking is no cure for 'Ruhr City'. The projection of disease burden shows that health status will decrease due to the demographic change. DALY estimates show the potential health gains, which can be won by implementing measures to reduce premature deaths and to prevent new cases.

Socio-biological status of Nigerian males with primary and secondary infertility.

Husbands in 100 consecutive couples complaining of lack of pregnancy after one year of normal intercourse were engaged in this study. Information from a structured questionnaire administered to these 100 men showed that 46% had primary infertility (had never impregnated any woman) and 54% secondary infertility (had in the past impregnated at least one woman irrespective of the outcome of the pregnancy). The mean ages (years) and standard error of mean for the primary and secondary infertile groups were 33.46 +/- 1.45 and 39.28 +/- 1.41 respectively. The difference was statistically significant (p < 0.05). Semen culture for growth of bacteria was positive in 59.3% of subjects with secondary infertility as opposed to 40.7% for primary infertility. The difference was, again, statistically significant (p < 0.05). These findings indicate that a higher proportion of husbands in infertile couples in a group of this environment had secondary infertility, were older and were more likely to harbour infections in their semen than those with primary infertility. Hence there should be a greater awareness of the significant involvement of bacterial infection of the genital tract of infertile Nigerian subjects than and before this factor should be taken into account in the prevention and treatment strategies for infertility in this and presumably other tropical countries.

Peripherally inserted central catheters: placement and use in a family practice hospital.

BACKGROUND: The peripherally inserted central catheter (PICC) is increasingly used in protracted intravenous therapy. The device has several advantages for family practice, but its use has been chiefly described in nursing and interventional radiology literature. We investigated the use of the PICC in a family practice teaching hospital. METHODS: Forty PICCs were inserted from 1993 to 1995 in 29 patients. Available records and radiographs were reviewed for indication, nature of placement attempts, indwelling time, PICC role in therapy, and attendant complications. RESULTS: Successful placement was achieved in 95 percent of instances requiring PICC use. Fluoroscopically guided placement, usually without venography, was found to be preferable to unguided bedside placement. In a few cases in which PICCs were placed, no other access was subsequently required to complete therapy. Few clinically serious complications were encountered. Most complications were related to placement at bedside. CONCLUSIONS: Our experience supports the PICC as a minimally invasive, economical alternative for protracted intravenous therapy. Fluoroscopically guided placement was found preferable to unguided bedside placement. Physicians ordering or placing PICCs should understand fully how to assess placement.

Haematogram and serum iron status of malnourished Nigerian children.

Haematological parameters, total serum iron, and total iron binding capacity (TIBC) concentrations were estimated in twenty protein energy malnourished (PEM) children, five kwashiorkor (K), five marasmus (M), five marasmic-kwashiorkor (M-K), and five undernourished (U) aged between one and five years on admission and after 18 days hospitalisation at Obafemi Awolowo University Teaching Hospital Complex. The Hospital diet for K and M-K consisted of 8% protein and 802 calories per litre while that for M and U consisted of 30% protein and 1350 calories per litre. After the period of 18 days of rehabilitation there was no significant (p > 0.05) difference (Student's t-test) in the weight for age. None of the haematological parameters was significantly different after rehabilitation for all the four types of PEM. Of the four types only Kwashiorkor with mean serum iron values of 15.6 +/- 1.51 micrograms/100 ml and 21.17 +/- 0.33 micrograms/100 ml on admission and after rehabilitation respectively was significantly (P < 0.05) different. More attention by the OAUTHC authorities needs to be paid to the management, feeding and diet given to these children so that there will be a greater and more rapid improvement in their rehabilitation.

The effect of antibacterial agents on plasma vitamin C levels.

Previous report on the estimation of plasma ascorbic acid levels in patients with chronic osteomyelitis indicated that the plasma ascorbic acid level is reduced in patients on antibiotics. The plasma study of the effects of anti-bacterial agents on plasma ascorbic acid in vitro, was carried out to substantiate the hypothesis than these agents lower plasma ascorbic acid levels. Increasing amounts of each of seven anti-bacterial agents: ampicillin, chloramphenicol, cefotaxime, gentamycin, benzyl and procaine penicillin combination (seclopen), co-trimoxazole, and streptomycin significantly (P < 0.01, r = -0.9587) reduced plasma vitamin C levels in vitro. There was moderate but insignificant reduction in plasma vitamin C levels with clindamycin (r = -0.799). The reduction of the plasma vitamin C levels observed in the presence of the eighth anti-bacterial agent, clindamycin, lacked significance (r = -0.799). The cause of this reduction of plasma vitamin C levels by anti-bacterial agents in vitro is not yet understood. A supplement of vitamin C may be required in patients on anti-bacterial agents.

Plasma biochemical parameters in Nigerian children with protein energy malnutrition.

Eleven plasma biochemical parameters were estimated in a total of 28 children with protein-energy malnutrition (PEM): 7 children each category of marasmus, kwashiorkor, marasmic-kwashiorkor and undernutrition with ages between 8 and 48 months. The estimations were performed on admission and 8 to 24 days after treatment at the Obafemi Awolowo University Teaching Hospitals Complex, Nigeria. Plasma sodium, potassium, chloride, bicarbonate and albumin levels were significantly (p < 0.05) higher after treatment than on admission. Calcium however, showed no significant change. Total protein and cholesterol were significantly (p < 0.05) raised after treatment for all the PEM types except undernutrition and kwashiorkor respectively. Globulin, urea and creatinine were significantly (p < 0.05) raised after treatment for kwashiorkor. These biochemical findings support the claims of clinical improvement in PEM children after a minimum of 18 days of treatment at the OAUTHC in Nigeria.

PIP: 11 plasma biochemical parameters were estimated in 28 children aged between 8 and 48 months with protein-energy malnutrition (PEM): 7 children each in the categories of marasmus, kwashiorkor, marasmic-kwashiorkor, and undernutrition. 8 ml of blood was obtained from each of the 7 children with marasmus, kwashiorkor, marasmic-kwashiorkor, and undernutrition, respectively, on admission to the children's ward of the Obafemi Awolowo University Teaching Hospital Complex (OAUTHC), Ile-Ife, Nigeria, and put into lithium heparinized tubes. The children were hospitalized for 18 and 24 days and fed the diet for PEM in the OAUTHC. 8 ml of blood was again taken from the children just before they were discharged. The percentage of recovery weight ranged between 74.4 and 86.4. Analysis of variance showed significance (p 0.05) for all types of PEM for plasma sodium, bicarbonate, urea, total protein, albumin, and globulin. The levels of plasma electrolytes comprising potassium, sodium, chloride, and bicarbonate were significantly (p 0.05) higher after recovery for all 4 types of PEM. There was also a significant (p 0.05) increase in plasma albumin levels in all 4 types of PEM. Plasma total protein levels were significantly increased in all types of PEM except undernutrition. The plasma globulin fraction which contains immune elements for body defense may be more tenaciously retained in PEM than albumin and only kwashiorkor showed a significant (p 0.05) increase after treatment. Plasma urea levels were significantly (p 0.05) higher after treatment than before for marasmus and kwashiorkor, the most protein deficient states in PEM. Plasma creatinine levels after treatment were significantly (p 0.01) lower for marasmic-kwashiorkor after treatment than on admission. The observed rise in kwashiorkor may reflect the increase in muscle formation and activity, while its decrease in marasmic-kwashiorkor possibly reflects increased renal function and efficiency.

Rabbit knee immobilization: bone remodeling precedes cartilage degradation.

This study analyzed processes underlying osteoporosis and osteoarthrosis after short-term immobilization of the right hind limb of postadolescent (2.8 kg) and mature (4.0 kg) rabbits. After 3 weeks, the lateral posterior aspect of the lateral tibial plateau and the lateral femoral condyle of the immobilized limb exhibited prominent subchondral vascular eruptions. Femoral metaphyseal bone density decreased 27 and 18% in the immobilized limbs of postadolescent and mature rabbits, respectively. Calcein green fluorescence increased 1.9-fold (p less than 0.001) in the metaphyseal trabeculae of immobilized femurs. With immobilization, sulfate incorporation into femoral cartilage glycosaminoglycan increased, although total cartilage glycosaminoglycan and hydroxyproline levels were unchanged. Thymidine incorporation into DNA increased four- to fivefold in tibial and femoral cartilage of the immobilized limb. In this study, bone loss and remodeling preceded erosive cartilage degradation.

Effects of an aqueous extract of cotton seed (Gossypium barbadense Linn.) on adult male rats.

Twenty adult male rats per group in 4 treatment groups were injected intraperitoneally at 08.00 hours with 0.1 ml of an aqueous cotton seed extract (Gossypium barbadense Linn.) (Malvaceae) in concentrations of (a) 105.25, (b) 21.21, (c) 4.65, (d) 2.325 mg ml-1 (kg body weight)-1, respectively. A fifth group (control) was given 0.1 ml of pyrogen free distilled water per rat. Five rats per treatment group were sacrificed at 2, 8, 24 and 168 hours respectively after treatment. Plasma follicle stimulating hormone (FSH) and luteinizing hormone (LH) showed no change. Plasma testosterone was lower (p less than 0.05) than that of control at 2 and 8 hours, with recovery by 168 hours post treatment. Plasma creatinine was raised by 2 hours, with recovery by 8 hours. Plasma urea rose gradually but persistently to a maximum of 168 hours. Plasma aspartate (AST) and alanine (ALT) transaminases were significantly higher (p less than 0.001) than that of controls throughout the study. Testicular histology showed early germ cell disorganization followed by progressive fibrosis (sperm cytoskeleton) by 24 hours. There was evidence of recovery by 168 hours. It is concluded that aqueous extract of cotton seed meal contains substances that can rapidly cause damage to testicular, liver, kidney and muscular tissues.

Steroidal contraceptives and changes in individual plasma phospholipids: possible role in thrombosis.

The changes in the levels of individual phospholipids were studies in women during prolonged use of three types of steroidal contraceptive preparation: high-dose combined pills (Noriday 1 + 50 Fe); low-dose combined pills (Nominest Fe) and progestin-only injectables (Depo-Provera). Women on high-dose combined pills had significantly higher (p less than 0.05) mean lysophosphatidylcholine (LPC), sphingomyelin (SPH), phosphatidylserine (PS) and phosphatidylethanolamine (PE) levels, respectively, than the women on low-dose combined pills, progestin-only injectables and the controls, respectively. Women on low-dose combined pills had significantly lower (p less than 0.01) mean LPC and PS levels, respectively, than the controls, while women on progestin-only injectables had significantly lower (p less than 0.01) mean PS and PE levels, respectively, than the controls. Based on the reported high activities of PS and PE in hemostasis, the PE/total plasma phospholipids, PS/total plasma phospholipids and the sum of PE and PS/total plasma phospholipids ratios were calculated to assess the possible overall effect of the changes in plasma phospholipids in steroidal contraceptive users. The results obtained using these indices agree with some earlier reports of an estrogen dose-dependent risk/incidence of thrombosis in steroidal contraceptive users. It is concluded that the observed dose-dependent estrogen-induced alterations in phospholipids, and, most especially, the PE and PS fractions may bear a relationship with thrombotic conditions.