Reply to ``Comment on `Inverse exciton series in the optical decay of an excitonic molecule' "

As a reply to the Comment by I.S. Gorban {\it et al.} (Phys. Rev. B, preceding paper) we summarize our criticism on their claim of the first observation of the $M$ series in $\beta$-ZnP$_2$. We support our analysis by reporting the first observation of inverse {\it polariton} series from the excitonic molecules selectively generated at ${\bf K}_m \simeq {\bf 0}$ in a CuCl single crystal. This observation and its explanation within the bipolariton model complete our proof of the biexcitonic origin of the inverse series.Comment: The Comment by I.S. Gorban et al. has been rejecte

In vitro susceptibility of clinical isolates of Mycobacterium tuberculosis to cefadroxil—a cephalosporin antibiotic

The bactericidal activity (BA) of cefadroxil, a semisynthetic cephalosporin antibiotic, against M. tuberculosis H37Rv was studied in Middlebrook 7H9 medium, Cefadroxil showed good BA (average fall of viable counts = log10 0.32 colony forming units/ml/day) against the log phase culture of M. tuberculosis H37Rv. Its minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were found to be 15 μg/ml or less. The MIC of cefadroxil for 29 clinical isolates of M. tuberculosis and a laboratory strain, M. tuberculosis H37Rv was also determined by agar dilution method using Middlebrook 7H11 agar as a screening procedure. The MIC of cefadroxil was found to be 10 μg/ml or less for M. tuberculosis H37Rv and 16 (55.1%) of 29 clinical isolates tested. The MIC for 3 of 10 drug sensitive and 9 of 19 drug resistant isolates was 40 or more, a concentration much higher than the peak plasma concentration (28 μg/ml) attained in human beings. The higher MIC observed in 12 of 29 clinical isolates irrespective of their susceptibility pattern requires further studies to assess the usefulness of cefadroxil in the treatment of tuberculosis

Optimal Kinematic Design of a Robotic Lizard using Four-Bar and Five-Bar Mechanisms

Designing a mechanism to mimic the motion of a common house gecko is the objective of this work. The body of the robot is designed using four five-bar mechanisms (2-RRRRR and 2-RRPRR) and the leg is designed using four four-bar mechanisms. The 2-RRRRR five-bar mechanisms form the head and tail of the robotic lizard. The 2-RRPRR five-bar mechanisms form the left and right sides of the body in the robotic lizard. The four five-bar mechanisms are actuated by only four rotary actuators. Of these, two actuators control the head movements and the other two control the tail movements. The RRPRR five-bar mechanism is controlled by one actuator from the head five-bar mechanism and the other by the tail five-bar mechanism. A tension spring connects each active link to a link in the four bar mechanism. When the robot is actuated, the head, tail and the body moves, and simultaneously each leg moves accordingly. This kind of actuation where the motion transfer occurs from body of the robot to the leg is the novelty in our design. The dimensional synthesis of the robotic lizard is done and presented. Then the forward and inverse kinematics of the mechanism, and configuration space singularities identification for the robot are presented. The gait exhibited by the gecko is studied and then simulated. A computer aided design of the robotic lizard is created and a prototype is made by 3D printing the parts. The prototype is controlled using Arduino UNO as a micro-controller. The experimental results are finally presented based on the gait analysis that was done earlier. The forward walking, and turning motion are done and snapshots are presented.Comment: 21 pages, 10 figures, Submitted for iNaCoMM 2023 conferenc

In vitro susceptibility of Mycobacterium tuberculosis to trifluoperazine

The reference strain, Mycobacterium tuberculosis H37Rv, 19 drug-sensitive and 15 drug resistant clinical isolates of M. tuberculosis were tested for their in vitro susceptibility to trifluoperazine (TFP), an antipsychotic drug, by broth dilution method. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of TFP against M. tuberculosis H37Rv were 8 and 32 mg/l, respectively. The distribution of the sensitive and resistant isolates, with respect to the MIC of TFP, was similar. The distribution of the sensitive and resistant isolates, with respect to the MBC of TFP, was different and the difference was statistically significant. The findings suggest that TFP is more bactericidal to drug-resistant isolates than to the sensitive isolates

Spontaneous Intracranial Hypotension

Introduction: Out of all the painful conditions, headache is one of most common cause of patients coming to hospital. Usually few patients present with orthostatic headache, which signifies low cerebrospinal fluid pressure. Case description: A 38-year-old female presented with intense headache in upright position, relieved on lying down in supine position. She was treated with analgesics and epidural blood patch. Discussion: Spontaneous intracranial hypotension is one of the treatable causes of headache. It can be detected by magnetic resonance imaging, which can reduce the morbidity and improve quality of life. Conclusion: As there is increase in availability of MRI, spontaneous intracranial hypotension can be detected easily

Bioluminescence assay of adenosine triphosphate in drug susceptibility testing of Mycobacterium tuberculosis

Twenty three clinical isolates of M. tuberculosis and the reference strain, M. tuberculosis H37Rv were tested for their susceptibility to trifluoperazine (TFP) by the standard broth dilution method and the bioluminescence assay. The results showed that in 15 of the 23 isolates, the minimal inhibitory concentration (MIC) was identical in both the methods and in the remaining 8 isolates the difference in the MIC values between the methods, was less than two fold and was not significant. The findings suggest that the measurement of adenosine triphosphate (ATP) by bioluminescence assay can be employed as an alternative method for the rapid screening of clinical isolates for their susceptibility to anti-mycobacterial agents

Experimental investigation and mechanism analysis: Effect of concentration and temperature on the heat transfer characteristics of novel MWCNT-mustard oil nanofluid

ABSTRACT. The bio-oils as alternative lubricating fluid are potential solution for the automotive and industrial mechanical systems. The development of novel renewable and non-toxic bio-oils with better heat transfer distinctiveness will strengthen the economy of farmers in the agricultural based countries. The most innovative approach to improve the heat transfer characteristics of bio-oils is converting it into nanofluids by dispersing nanomaterials which has extremely high heat transfer characteristics. In this study, MWCNT-Mustard oil nanofluids were formulated through ultrasonication and their dispersion stability was estimated through Zeta-potential technique.  The thermal stability of the MWCNT-Mustard oil nanofluids are estimated through thermogravimetric analysis and concentration and temperature dependent density, thermal conductivity and specific heat capacity of MWCNT-Mustard oil nanofluids are also determined and their characteristics are discussed. The heat transfer characteristics of MWCNT-Mustard oil nanofluids observed through the heat pipe test rig at different inlet temperatures, mass flow rate of nanofluids and Reynolds number. The results exhibits that the dispersion of MWCNT enhances the heat transfer characteristics of MWCNT-Mustard oil nanofluids.   KEY WORDS: Non-toxic bio-oils, Nanomaterials, Nanofluids, Thermogravimetric analysis, MWCNT, Mustard oil Bull. Chem. Soc. Ethiop. 2022, 36(3), 675-686.                                                                DOI: https://dx.doi.org/10.4314/bcse.v36i3.1

Reaction of Hydrazine Hydrate with Oxalic Acid: Synthesis and Crystal Structure of Dihydrazinium Oxalate

The reaction of oxalic acid with hydrazine hydrate (in appropriate mole ratio) forms the dihydrazinium oxalate under specific experimental condition. The title compound is a molecular salt containing two discrete hydrazinium cations and an oxalate anion. The oxalate anion is perfectly planar and there is a crystallographic centre of symmetry in the middle of the C-C bond. The C-O bond distances are almost equal indicating the presence of resonance in the oxalate ion. The crystal packing is stabilized by intermolecular N-H…Oand  N-H…Nhydrogen bonds. The oxalate ions are linked together end to end through hydrogen bonds (via N2H5+ ions) and run parallel to the [101] direction. It is interesting to note that each oxalate group in the structure is surrounded by six hydrazinium ions through hydrogen bonding. Similarly, each hydrazinium ion is surrounded by three oxalate and one hydrazinium ion.KEY WORDS: Hydrazine, oxalic acid, dihydrazinium oxalate, crystal structure

Knowledge, attitude, and practices among clinically exposed medical students and interns towards COVID-19 vaccine in a tertiary care hospital, Kanyakumari district: a cross-sectional survey

Background: Several COVID-19 vaccines have been approved against coronavirus disease and its distribution to different countries. The study is mainly done to determine the knowledge, attitude, and practice among clinically exposed medical students and interns toward COVID-19 vaccine.Methods: A cross-sectional study was conducted from June 2022 to August 2022 in a tertiary care hospital. Using questionnaires, the knowledge, attitude, and practice among medical students and interns were assessed, and they were then analysed and categorised accordingly. Then the students were given awareness regarding COVID-19 vaccine.Results: The questionnaires were distributed among students and interns, and responses were collected. A total number of participants (n=300), out of which the majority of responders were second-year students 89 (29.6%). Overall, 39.75% had high-grade knowledge, 43.5% had a positive attitude and 37.5% had good practice regarding the COVID-19 vaccine. The results show that 81.2% of interns had high-grade knowledge, 76.6% possess a positive attitude and 71.9% of good practice and preventive measures towards COVID-19 vaccine.Conclusions: Our study concludes that there were certain gaps in knowledge, attitude, and practice among second and third-year medical students when compared with final-year medical students and interns