Papers by Sheikh Ahnaf Hasan

Systematic Reviews in Pharmacy, 2021
Synthesis and characterisation two Schiff bases[L1] (N2Z,N6Z)-N2,N6-bis(4-((E)- anthracen-9-ylmet... more Synthesis and characterisation two Schiff bases[L1] (N2Z,N6Z)-N2,N6-bis(4-((E)- anthracen-9-ylmethyleneamino)-1,5-dimethyl-2- phenyl-1H-pyrazol-3(2H)- ylidene)pyridine-2,6-diamine Synthesis via reaction of 2,6-diaminopyridine, 4- aminoantipyrine and 9- anthracenecarboxaldehyde with mole ratio (1:2:2) respectively two steps. And[L2] (N1Z,N2Z)-N1,N2-bis(4-((E)-anthracen-9- ylmethyleneamino)- 1,5-dimethyl-2- phenyl-1H-pyrazol-3(2H)-ylidene)-4- methylbenzene-1,2-diamine Synthesis from reaction of o-phenylendiamine ,4- aminoantipyrine and 9-anthracenecarboxaldehyde with mole ratio (1:2:2) respectively two steps. A new series of transition metal complexes of Mn(II), Co(II), Ca(II), Cd(II) , Zn(II) and pd(II) were synthesized .The structural features were derived from their elemental analyses, infrared, UV-visible spectroscopy, 1HNMR,13CNMR spectroscopy, thermal gravimetric analyses spectral ,magnetic susceptibility measurement, chloride content and conductivity measurements. The electroni...

The study includes preparation and characterisation of mixed azo-linked Schiff-base ligands and t... more The study includes preparation and characterisation of mixed azo-linked Schiff-base ligands and their complexes. The starting material was isolated from the mixing of 2-amino pyridine diazonium salt with 2-amino-phenole and 4-amino-3hydroxy-1-naphthalene sulfonic acid respectively in 1:1 mole ratio in water. In this work, the formation of azo-linked Schiffbase ligands are reported. Ligands of the azo-linked Schiff-base was achieved by the reaction of starting material with 4(dimethylamino) benzaldehyde) (HL1 and HL). The complexes were prepared by mixing the azo-linked Schiff-base ligands with the metal salts; CoII, NiII and CdII in a 1:1:1 mole ratio. Ligands and complexes were characterised by analytical and spectroscopic analyses including; microanalysis, chloride content, thermal analysis, magnetic susceptibility for complexes, conductance, FTIR, UV-Vis and 1H-NMR spectroscopy. Physico-chemical techniques indicated complexes demonstrated six coordinate structures in the solid an...

Ibn AL- Haitham Journal For Pure and Applied Science, Dec 28, 2017
The precursor [W] [2-(2-(naphthalen-5-yl) diazenyl)-4-amino-3-hydroxynaphthalene-1sulfonic acid] ... more The precursor [W] [2-(2-(naphthalen-5-yl) diazenyl)-4-amino-3-hydroxynaphthalene-1sulfonic acid] was synthesized from reaction of diazonium salt with 1-amino-2-naphtol-4sulfonic acid. Then the tridentate Schiff base ligand type ONO was synthesized from the reaction of the precursor with salicyaldehyde in 1:1 mole ratio to produce the ligand H 2 L [2-(2-(naphthalen-5-yl) diazenyl)-4-(2-hydroxynaphthalen-3-yl)methyleneamino)-3-hydroxy salicyalene-1-sulfonic acid],the reaction achieved in methanol as a solvent under reflux. Spectroscopic methods IR, U.V, 1 H, 13 C-NMR was used to characterize the ligand. Complexes of [Cr III , Co II , Ni II and Cd II] ions were also prepared through reaction of ligand with metal salts in 2:1 mole ratio at reflux, using KOH as a base, ethanol as a solvent. Chloride content, molar conductivity and melting point measurements along with I.R and U.V-Vis, atomic absorption (A.A) spectroscopy were used to characterize the complexes. 1 H-NMR spectroscopy was used to characterize Cd complex. Thermal analysis was used to insure the presence of crystallized H 2 O molecule in the complexes structure. The following formula was proposed for Cr complex: K[Cr(L) 2 ]. H 2 O, while Co II , Ni II and Cd II complexes have the K 2 [M(L) 2 ].H 2 O formula. The biological activity of the prepared compounds was studied. Fluorescence properties of the prepared compounds were studied (at room temperature) which indicate that the ligand may behave as strong fluorescent emitter. The complexes also showed fluorescence characteristic with the ligand. The ligand revealed high relative intensity and its fluorescence peak were also shifted to the lower or higher wavelength when compared with the complexes.

Oriental Journal of Chemistry
The study includes preparation and characterisation of mixed azo-linked Schiff-base and DTCs liga... more The study includes preparation and characterisation of mixed azo-linked Schiff-base and DTCs ligands and their complexes. The starting material was isolated from the mixing of naphthyl amine diazonium salt with 2-aminophenolein a 1:1 mole ratio in water. In this work, the formation of azo-linked Schiff-base and DTCs ligands are reported. Ligand of the azo-linked Schiff-base was achieved by the reaction of starting material with 4-(dimethylamino)benzaldehyde) (HL 1). The DTCs was isolated by the reaction of (C 6 H 5) 2 NH with carbon disulphide in potassium hydroxide (L 2). The complexes were prepared by mixing the azo-linked Schiff-base ligand and DTCs ligand with the metal salts; Co II , Ni II , Zn II and Cd II in a 1:1:1 mole ratio. Ligands and complexes were characterised by analytical and spectroscopic analyses including; microanalysis, chloride content, thermal analysis, magnetic susceptibility for complexes, conductance, FTIR, UV-Vis and 1 H-NMR spectroscopy. Physico-chemical techniques indicated complexes demonstrated four and six coordinate structures in the solid and solution state. Biological activity of the ligands and their metal complexes were screened for their antimicrobial activity against four bacterial species (Escherichia coli and Enterobacter Gram-ve, (Bacillus stubtilis and Staphylococcus aureus Garam + ve.

Detection, 2016
Thirty-one samples of cigarettes have been collected from local markets of different types of ori... more Thirty-one samples of cigarettes have been collected from local markets of different types of origins. The samples were selected according to a survey distributed to smokers by paper and digital survey to see the most heavily traded among smokers and in addition to a number of questions to see how the awareness and the culture of smokers in diseases caused by smoking and considered this study the first survey in Iraq. The aim of this research is to assess the number of cancer cases due to cigarette smoking. Through the use of High-Purity Germanium system (HPGe) (efficiency 40%) we determinated the radionuclides in cigarette tobacco. The average values were (14.86 ± 3.76, 10.84 ± 3.13, 1050.64 ± 47.57) Bq/kg for Ra-226, Th-232 and K-40, respectively, and the excess lifetime of cancer risk values ranged from 0.54 to 130 at average of 76 per million person per year. Raeq values varied from 18.50 to 87.21.4 Bq/kg with an average value of 39.51 Bq/kg for tobacco samples. The annual effective dose (HE) varies from 16.38 µSv/y to 44.69 µSv/y with an average value of 24.97 µsv/y. The Annual Gonadal Dose Equivalent (AGDE) varies from 0.3 to 0.64 (mSv/y) with an average value of 0.42 for all tobacco samples under investigation.
International Journal of Nuclear Knowledge Management, 2008

The Scientific World Journal, 2013
A new macrocyclic multidentate Schiff-base ligand Na4L consisting of two submacrocyclic units (10... more A new macrocyclic multidentate Schiff-base ligand Na4L consisting of two submacrocyclic units (10,21-bis-iminomethyl-3,6,14,17-tricyclo[17.3.1.18,12]tetracosa-1(23),2,6,8,10,12(24),13,17,19,21,-decaene-23,24-disodium) and its tetranuclear metal complexes with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) are reported. Na4L was prepared via a template approach, which is based on the condensation reaction of sodium 2,4,6-triformyl phenolate with ethylenediamine in mole ratios of 2 : 3. The tetranuclear macrocyclic-based complexes were prepared from the reaction of the corresponding metal chloride with the ligand. The mode of bonding and overall geometry of the compounds were determined through physicochemical and spectroscopic methods. These studies revealed tetrahedral geometries about Mn, Co, and Zn atoms. However, square planar geometries have been suggested for NiIIand CuIIcomplexes. Biological activity of the ligand and its metal complexes against Gram positive bacterial strainStaph...

Journal of King Abdulaziz University-science, 1989
ABSTRACf. A nondestructive neutron activation analysis technique has been applied for rapid deten... more ABSTRACf. A nondestructive neutron activation analysis technique has been applied for rapid detennination of vanadium as a trace element in Egyptian crude oils (marine and land of Balayim source), using a conventional as well as cyclic modes of irradiation. While the fonner one is carried out by pneumatic transfer rabbit system coupled with the 2 MW ERR-I, the latter mode is perfonned by rapid fluid transfer system in conjunction with 5 Ci Pu/Be isotopic neutron source. A Ge(Li) detection system was used for data collection. Vanadium as a trace element in two samples of marine and land crude oils have been estimated and found to be44:!: 4.4and80:!: 8.0ppm respectively by cyclic activation analysis, which agree with the corresponding values of 45 :!: 2.4 and 92 :!: 4.6 ppm deduced by the conventional system. Both data are in fair agreement with previously reported values of cbemical analysis.
Nucleosides Nucleotides & Nucleic Acids, 2006
A new synthesis of 6-amino-1-hydroxyethoxymethyl-4 (5H)-oxopyrazolo[3, 4]pyrimidine (4) has been ... more A new synthesis of 6-amino-1-hydroxyethoxymethyl-4 (5H)-oxopyrazolo[3, 4]pyrimidine (4) has been mentioned. Compound 4 exhibited inhibition of amastigotes of Leishmania donovani to the extent of 89% at 30 μg/mL, whereas iso-guanine analogue 5 had the inhibition only to the extent of 52.8% at 100 μg/mL in vitro. In hamster model the maximum inhibitory response for compound 4 against amastigotes multiplication was
Conclusions BdbServer++ has highlighted some of the areas of opportunity for the current middlewa... more Conclusions BdbServer++ has highlighted some of the areas of opportunity for the current middleware. This has been fed back into the development process for future releases. The issue of data location is however, one where ideal solutions remain a distant prospect. ...
IETE Journal of …, 2009
Mobile-to-mobile communication becomes necessary in many emerging wireless communication systems.... more Mobile-to-mobile communication becomes necessary in many emerging wireless communication systems. Characteristics of mobile-to-mobile communication channel have been studied through a geometrical single bounce scattering model and analytical expressions for angle of arrival and time of arrival probability density functions have been derived for such models. Analytical expressions have been verified through computer simulations. This paper aims to provide a better understanding of mobile-to-mobile channel behavior in terms of the parameters studied.

Two-Phase Gas/Liquid Flow Rate Estimation During Closed-Chamber Testing
Journal of Canadian Petroleum …, 1991
Flow rate estimation constitutes one of the most important tasks in a closed-chamber test (CCT). ... more Flow rate estimation constitutes one of the most important tasks in a closed-chamber test (CCT). During a CCT flow period, the reservoir fluids are allowed to accumulate in the drill-string, and are not produced to the surface. This operational aspect differentiates the CCT from a conventional drill stem test (DST), where the flow rate is measured at the surface unless the well kills itself. A flew methodology has been developed to compute the flow rate of each phase during two-phase gas/liquid flow, frequently encountered in a DST. By measuring pressure at both the wellhead and above the downhole flow-control valve, the changing liquid height is calculated by considering two-phase flow, including the effects of gas and liquid compression, friction and mass transfer. The knowledge of rising liquid height during the flow period allows calculation of liquid flow rate, while the gas flow rate is computed from the material-balance considerations. Several field examples are used to verify the new method. Indeed, good agreement is obtained between the measured liquid recovery in the drill pipe and that predicted by the new method. We further show that the computed rates enhance pressure transient analysis. Appropriate equations are also presented for both single-phase gas and liquid flow. Introduction Interpretation of DST or initial flow period data has been attempted by the hydrologists and petroleum engineers alike over the past 35 years. In these tests, the flow typically occurs against an open wellhead valve, allowing maximum possible flow rate. This is the so-called ‘slug-rest’ where fluid withdrawal from formation into the wellbore occurs at a high initial rate, followed by the continuous rate decline with consequent pressure increase. The flow ceases when the downhole valve is shut in or when the hydrostatic heads of the well bore fluids balance the formation pressure. In other words, reservoir fluids are not produced at the surface in a slug test. In contrast, a near-constant downhole flow rate may be possible in a conventional DST because critical flow is attainable across the downhole choke. The resulting flow rate may be sustained by producing the reservoir fluids to the surface. On the other hand, in a closed-chamber test, the fluids are also not produced at the surface, by design, by keeping the wellhead valve closed. The rate decline in this case is more rapid than a slug test because of smaller pressure differential between the reservoir and the sandface. As gas above the liquid column gets progressively compressed, the late time pressure behavior differs markedly from a slug test. The name closed-chamber test or CCT is used in a generic sense and that test data may be gathered from many hardware configurations, such as, DST(1), temporary perforation completion(2,3) and backsurge perforation cleaning(4). This, pressure and flow behavior are quite different in these three principal tests conducted to evaluate a zone's initial productive potential. The main objective of this work is to present a method to compute the flow rate of a two-phase gas/liquid mixture during the flow period.

European journal of …, 2004
Objective: To compare the outcome of life insurance and mortgage applications of adults with cong... more Objective: To compare the outcome of life insurance and mortgage applications of adults with congenital heart disease (CHD) with controls and at different severities of CHD. Methods: Two hundred and ninety-nine adult CHD patients underwent a questionnaire-based interview by a trained nurse. They were asked to give an identical questionnaire to a friend to act as a control. One hundred and seventy-seven controls replied. CHD patients were classified into three categories based on severity. Comparisons were made between matched controls and between different severities of CHD. Results: Similar proportions of the CHD group (59%) had applied for life insurance as matched controls (56%). Compared to controls, significantly more of the adults with CHD who had applied for life insurance have been refused (34 vs 4%, P , 0:0001) or asked to pay extra (37 vs 6%, P ¼ 0:0002). Mortgage application rate was also similar in both groups with more of the CHD patients refused than matched controls (20 vs 3%, P ¼ 0:004). These differences in both life insurance and mortgage remain significant when the cases and controls are matched by employment status and NYHA functional class. There was no significant difference in life insurance and mortgage application outcome between the groups of mild, significant and complex CHD. Conclusions: Adults with CHD are significantly more likely to have difficulty obtaining life insurance or a mortgage than controls. Refusal rates appear to be independent of the severity of CHD. This suggests that the label of CHD may have a negative impact despite the lesion being minor and that the outcome of an individual application is difficult to predict based on the severity of the CHD. The increasing numbers of adults with CHD suggest that this problem is likely to increase and needs to be addressed as it can have a major impact on the patient's quality of life.
Physics letters B, 2001
The K 0 S K 0 S final state in two-photon collisions is studied with the L3 detector at LEP. The ... more The K 0 S K 0 S final state in two-photon collisions is studied with the L3 detector at LEP. The mass spectrum is dominated by the formation of the f 2 (1525) tensor meson in the helicity-two state with a two-photon width times the branching ratio into KK of 76 ± 6 ± 11 eV. A clear signal for the formation of the f J (1710) is observed and it is found to be dominated by the spin-two helicity-two state. No resonance is observed in the mass region around 2.2 GeV and an upper limit of 1.4 eV at 95% C.L. is derived for the two-photon width times the branching ratio into K 0 S K 0 S for the glueball candidate ξ(2230).

Transcranial magnetic stimulation (TMS) is a very popular tool used within neuroscience. This and... more Transcranial magnetic stimulation (TMS) is a very popular tool used within neuroscience. This and other associated techniques allow the in vivo investigation of cortical excitability, cortical connectivity and cortical plasticity. Schizophrenia is a brain disorder and various theories other than the dopamine hypothesis have been developed to describe its underlying neurobiology. Supported by animal and post mortem studies, findings from TMS studies indicate that schizophrenia is a disease of reduced cortical inhibition and impaired intra-and intercortical connectivity. Further studies using repetitive TMS and other plasticity-inducing techniques have shown that cortical plasticity is altered in schizophrenia patients, supporting the recently discussed plasticity deficiency theory of schizophrenia. This review gives an introduction to the most frequently applied techniques, describes findings in schizophrenia patients and discusses these findings with regard to the neurotransmitters and associated receptors involved. In summary, there is emerging evidence of an important pathophysiological interplay between reduced inhibition, impaired connectivity and reduced plasticity in schizophrenia patients. Gammaaminobutyric-acid-receptors and glutamtergic N-Methyl-D-aspartic-acid-receptors are most likely to be involved in this complex interplay, which may reflect a disturbed signal-to-noise ratio in schizophrenia patients. This review will discuss this issue with regard to the available treatment options and will give implications for future research and therapeutic strategies regarding disinhibition and neuroplasticity in schizophrenia.

Archives of Disease in Childhood, 1998
Background-Thoracentesis and antibiotics remain the cornerstones of treatment in stage I empyema.... more Background-Thoracentesis and antibiotics remain the cornerstones of treatment in stage I empyema. The management of disease progression or late presentation is controversial. Open thoracotomy and decortication is perceived to be synonymous with protracted recovery and prolonged hospitalisation. Advocates of thoracoscopic adhesiolysis cite earlier chest drain removal and hospital discharge. This paper challenges traditional prejudice towards open surgery. Methods-A five year audit of empyema cases referred to a regional cardiothoracic surgical unit analysing previous clinical course, surgical management, and outcome. Results-Between February 1992 and February 1997, the number of referrals to this centre increased dramatically. Twenty two children were referred for surgery (15 boys, seven girls; age range, 0.5-16 years). Before referral, patients had been unwell for 6-50 days (median, 15), had been treated with several antibiotics, and had undergone chest ultrasound (15 patients), computed tomography (five patients), pleural aspiration attempts (13 patients), and intercostal drainage (seven patients). The organism responsible was identified in only two cases (Streptococcus pneumoniae). Three patients had intraparenchymal abscess formation. Eighteen patients underwent open thoracotomy and decortication. Drain removal was performed on the first or second day. Fever resolved within 48 hours. Median hospital stay was four days. All patients had complete clinical and radiological resolution. Conclusions-Treatment must be tailored to the disease stage. In stage II and III diseases, open decortication followed by early drain removal results in rapid symptomatic recovery, early hospital discharge, and complete resolution. In the early fibrinopurulent phase, alternative strategies should be considered. However, even in ideal cases, neither fibrinolysis nor thoracoscopic adhesiolysis can achieve more rapid resolution at lower risk.

The 65 kD heat shock protein (HSP) has been implicated in the aetiology of recurrent aphthous sto... more The 65 kD heat shock protein (HSP) has been implicated in the aetiology of recurrent aphthous stomatitis (RAS). We have previously demonstrated that peptide 91-105 derived from the sequence of mycobacterial 65 kD HSP stimulates specifically lymphocytes from patients with RAS. In this investigation, we show that both CD4 + and CD8 + T cells were significantly stimulated with mycobacterial peptide 91-105. In contrast, the human homologous peptide 116-130 stimulated only CD4 + T cells. Inhibition studies showed that CD4 + T cells were class II restricted, whereas CD8 + T cells were class I restricted. We then used truncated or substituted peptides, and demonstrated that residues 95-105 appear to be important, and residue 104(Arg) critical, in stimulating the T cells. Thus, peptide 95-105 may constitute a T-cell proliferative epitope in RAS. We postulate that the high load of microorganisms that colonize the oral mucosa may initiate an immune response by the microbial HSP 65derived peptide 95-105, stimulating the numerous Langerhans cells in the oral mucosa to activate a cross-reacting immune response to the homologous peptide 116-130 within the epithelial HSP 60, initiating the immunopathological changes that lead to RAS.

Background: Chronic myeloid leukaemia (CML), with a median age of 40 years, is one of the commone... more Background: Chronic myeloid leukaemia (CML), with a median age of 40 years, is one of the commonest haematological malignancies in Nigeria. Cytoreductive agents, which were hitherto the mainstay of treatment, neither induce cytogenetic nor haematologic remission. Alphainterferon (á-IFN), an endogenous glycoprotein with cytotoxic and natural killer cell enhancer effects has been found to induce haematologic and cytogenetic remission in patients with CML, but neuro-psychiatric complications of á-interferon (á-IFN) usage were not reported in Nigeria. Objective: To report a case of deliberate self-harm in University Lecturer as a side effect of á-IFN in the treatment of CML Method: Clinical and laboratory follow up of a patient receiving á-IFN in the management of CML from the time of diagnosis of CML to the point of loss of contact. Result: Severe depression is a complication that may adversely influence the clinical outcome of á-IFN usage Conclusions/Recommendations: Although interferon related depression is uncommon, it is suggested that pre-therapy interferon assays and neuro-psychiatric assessment are carried out in prospective users of á-IFN
Physical review letters, 1997
The lifetimes of B + and B 0 mesons are measured using a sample of 150 000 hadronic Z 0 decays co... more The lifetimes of B + and B 0 mesons are measured using a sample of 150 000 hadronic Z 0 decays collected by the SLD experiment at the SLAC Linear Collider between 1993 and 1995. Two analyses are presented in which the decay length and charge of the B meson are reconstructed. ...
Physics Letters B, 1990
We have measured the cross-section of the reaction e + e − → γγ at center of mass energies around... more We have measured the cross-section of the reaction e + e − → γγ at center of mass energies around the Z 0 mass. The results are in good agreement with QED predictions. For the QED cutoff parameters the limit of Λ + > 103 GeV and Λ − 118 GeV are found. For the decays Z 0 ...
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Papers by Sheikh Ahnaf Hasan