Al2O3/ZrO2 dual-dielectric Gr/CNT nanoribbon vertical tunnel FET based biosensor for genomic classification and S-protein detection in SARS-CoV-2

The ongoing genetic mutation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) possesses the capacity to inadvertently lead to an increase in both the rates of transmission and mortality. In this study, we showcase the use of an Al2O3/ZrO2 Dual-Dielectric Gr/CNT Nanoribbon vertical tunnel field-effect transistor biosensor for the purpose of detecting spike proteins of SARS-CoV-2 in clinical samples. The proteins mentioned above are situated within the protein capsids of the virus. The effectiveness of the suggested detector has been assessed through measurements of the alteration in current drain. The present study utilizes the dielectric coefficient analogue of viral proteins as a substitute for biomolecules that exhibit internal hybridization nanogaps. The high sensitivity of the suggested detector, as evaluated on a scale ranging from 0 to 115, suggests its potential as a high-quality sensing instrument. The purpose of this study is to examine the sensitivity of DNA charge density with the aim of identifying any alterations in the virus that may impact its ability to spread and infect humans. The chromosomal composition of SARS-CoV-2 has been determined. The CMC Research Centre, situated in Vellore, Tamil Nadu, India, conducted an examination of SARS-CoV-2 samples. The scientists possess the capability to do genome sequencing on these specimens, so facilitating the examination of mutation patterns and the dispersion of different clades. A total of 250 different mutations were found out of the 600 sequences that were evaluated. The sequencing data consists of a complete collection of 250 distinct variants, including 150 missense mutations, 80 synonymous mutations, 15 mutations in noncoding regions, and 5 deletions. The comprehension of genetic variety is significantly dependent on these mutations. The proposed detector is connected to a variety of previously documented biosensors based on field-effect transistors (FETs), which are employed for the examination of genetic modifications.

Hybrid Silicon Substrate FinFET-Metal Insulator Metal (MIM) Memristor Based Sense Amplifier Design for the Non-Volatile SRAM Cell

Maintaining power consumption has become a critical hurdle in the manufacturing process as CMOS technologies continue to be downscaled. The longevity of portable gadgets is reduced as power usage increases. As a result, less-cost, high-density, less-power, and better-performance memory devices are in great demand in the electronics industry for a wide range of applications, including Internet of Things (IoT) and electronic devices like laptops and smartphones. All of the specifications for designing a non-volatile memory will benefit from the use of memristors. In addition to being non-volatile, memristive devices are also characterized by the high switching frequency, low wattage requirement, and compact size. Traditional transistors can be replaced by silicon substrate-based FinFETs, which are substantially more efficient in terms of area and power, to improve the design. As a result, the design of non-volatile SRAM cell in conjunction with silicon substrate-based FinFET and Metal Insulator Metal (MIM) based Memristor is proposed and compared to traditional SRAMs. The power consumption of the proposed hybrid design has outperformed the standard Silicon substrate FinFET design by 91.8% better. It has also been reported that the delay for the suggested design is actually quite a bit shorter, coming in at approximately 1.989 ps. The proposed architecture has been made significantly more practical for use as a low-power and high-speed memory system because of the incorporation of high-K insulation at the interface of metal regions. In addition, Monte Carlo (MC) simulations have been run for the reported 6T-SRAM designs in order to have a better understanding of the device stability.

Hemiuterus with functional non-communicating horn in a young female

Background

Mullerian duct anomalies are a broad spectrum of congenital anomalies of the female genital tract presenting with variable symptoms like infertility, amenorrhoea, dysmenorrhea, pelvic endometriosis, and poor obstetric outcomes. Unicornuate uterus or hemiuterus occurs as a result of abnormal formation or failure of formation of the contralateral part.

Case presentation

We present a rare case report of hemiuterus with functional non-communicating horn along with hematometra in a 15-year-old female who presented with severe dysmenorrhoea since her menarche. Pelvic Ultrasonography demonstrated inconclusive findings of a heterogenous lesion in the right pelvic cavity adjacent to the uterus. Further, pelvic MRI revealed a hemiuterus on the left side with a normal endometrial cavity and a well-defined functional non-communicating horn on right side. The diagnosis of European Society of Human Reproduction (ESHRE) Classification U4a uterine anomaly (left hemiuterus with functional non-communicating horn on right side) was established.

Conclusions

ESHRE Class U4a comprises of hemiuterus with a functional rudimentary horn. This is considered clinically significant as it may lead to further complications, such as hematometra or ectopic pregnancy in the rudimentary horn. Hence, the correct identification of this entity is essential as laparoscopic removal is the current recommended management.

Are carcinogens electron acceptors? A novel hypothesis

Carcinogens play a key role in cancer initiation. Conventional theories support the concept of genetic changes inducing tumorigenesis through proteomics and metabolomics which lead to cancer development. Current research provides evidence that metabolic genes may be altered long before mutation of tumour suppressor genes, strongly suggesting that metabolic changes may be preceding the changes seen at a genetic level. Since cancer has long been known to occur through gene regulation, an impaired cellular respiration without utilizing mitochondrial function has been an area of active interest. We hypothesize the activity of carcinogens as electron acceptors to disrupt the normal glycolysis cycle happening in a cell by acting as positive ligands. The continuous restoration of NAD+ to cytosol by oxidation of NADH with carcinogen as electron acceptor creates a metabolic pathway to assist in the carcinogenic process. This metabolic pathway continues through an adaptive process, supplemented by pyruvate converting to lactate providing a constant pool of NAD+ to continue the glycolytic pathway. We also hypothesize that carcinogenesis occurs as a precursor to metabolic stress which may promote altered genetic and protein expression causing aberrant epigenetic and cell signaling pathways.

Linear and nonlinear temperature-dependent transmission/absorption characteristics of cadmium telluride crystal for terahertz generation

This paper reports on the temperature-dependent investigation of linear and nonlinear transmission/absorption characteristics of CdTe crystal in the 300-408 K range using 780-970 nm tunable wavelengths of 140 fs pulses obtained from a Ti:Sapphire laser at 80 MHz repetition rate. The same pulses were also used for terahertz generation. The linear transmission/absorption properties were measured using a specially improvised temperature-tuned spectrophotometer in the 500-1500 nm wavelength range. The linear absorption of 750 nm wavelength gradually increases with respect to a rise in the temperature, and transmission becomes zero at 408 K. Nonlinear absorption induced by femtosecond pulses shows a sudden drop of 18% in transmission above the 800 nm range, due to electron-phonon interaction, which affects the strength of the terahertz signal. It is also responsible for change in the temperature along with the linear shift in the refractive index of the crystal.

Temperature-dependent terahertz spectroscopy and refractive index measurements of aqua-soluble and plastic explosives

The paper reports the temperature-dependent time domain terahertz spectroscopy of premium aqua-soluble and plastic explosives such as NH₄NO₃, TNT, and RDX between 0.1 and 2.2 THz. Tunable terahertz radiation was generated using ZnTe crystal as a source, and a photoconductive antenna was used as a detector. The temperature-dependent study was carried out between 30°C and 200°C in a specially designed oven. The signature peaks of RDX and TNT present at 0.82 and 1.60 THz, respectively, show a strong redshift, whereas the NH₄NO₃ molecule shows a comparatively small shift. The high-temperature-based redshift phenomenon is just the opposite of the blueshift recorded at low temperatures. In addition, the temperature-dependent absorption coefficient data of these molecules support the change in the concentration of the NO₂ molecule. We have also ascertained the temperature-dependent refractive indices of these molecules between 0.1 and 2.0 THz, which confirms the effect of temperature on the refractive indices. Finally, the signature peak of RDX with respect to the reduction in the weight concentration of RDX in the Teflon matrix was studied at 0.82 THz.

Trace metal distribution, assessment and enrichment in the surface sediments of Sundarban mangrove ecosystem in India and Bangladesh

Comparative study of trace metals distribution in the surface sediment of Sundarban mangrove ecosystem in India and Bangladesh is one of the primary baseline study done so far. Trace metal distribution assessment covering lower salinity zone to higher salinity zone was done along Matla River (tidal river) in Indian side and freshwater zone to higher salinity zone along Passur River in Bangladesh side of Sundarban; representing anthropogenic influenced area, agricultural area, tourist site and pristine area. Trace metals distribution in the surface sediments of Sundarban mangrove ecosystem shows relatively higher value of trace metals, Co, Cr, Cu, Fe, Ni, Pb and Zn in Indian part when compared to Bangladesh. Enrichment factor shows the highest enrichment of Pb in both parts of Sundarban mangroves. Co, Cr, Cu, Pb and Zn show EF>1 indicates sediment contamination from anthropogenic activities. Cr, Ni and Pb were found to have moderate accumulation in geoaccumulation index with Fe showing high accumulation. Normalized data of trace metals shows 87.5% from Indian site and 80% of Bangladesh site as outlier, indicating anthropogenic influence. Out of total sampling site 50% of Indian and 40% of Bangladesh site show trace metal values enriched more than predicted value of trace metals indicating Indian part have more polluted sites than Bangladesh side of Sundarban, which is also confirmed by enrichment factor, I-geo and normalization values in both the sides.

A population study of first and subsequent pregnancy smoking behaviors in Ohio

OBJECTIVE

The objective of this study is to identify maternal characteristics associated with non-smoking during a subsequent pregnancy after first pregnancy smoking.

STUDY DESIGN

We conducted a retrospective population-based analysis of Ohio vital birth records from 2007 to 2013. We used logistic regression to calculate adjusted odds ratios with 95% confidence intervals for detection of characteristics associated with non-smoking during a subsequent pregnancy after first pregnancy smoking.

RESULTS

Among 75 190 mothers, 75.6% were non-smokers and 13.7% were smokers during both pregnancies. During their first pregnancy, 49.7% of 15 075 smokers quit. Of them, 50.1% remained non-smokers during their subsequent pregnancy. Women who reduced, but continued smoking during their first pregnancy, were more than five times as likely to smoke during their subsequent pregnancy than women who quit (odds ratio (95% confidence interval): 2.85 (2.43 to 3.35) vs 0.55 (0.45 to 0.67)).

CONCLUSION

Interventions targeting complete cessation, rather than reduction in smoking among first-time mothers, may be the most effective at optimizing long-term health benefits.

Doxorubicin enhances (131)I-rituximab induced cell death in Raji cells

AIM

There are various therapeutic modalities of treatment for non-Hodgkin's lymphoma, but with certain limitations, hence, investigating the scope of combined therapeutic approach.

MATERIALS AND METHODS

In this article, cellular toxicity, apoptosis and expression of mitogen-activated protein kinase signaling pathway proteins were investigated in Raji cells preincubated with doxorubicin followed by (131)I-rituximab (rituximab radiolabeled with Iodine-131) treatment.

RESULTS

It was found that the (131)I-rituximab in combination with doxorubicin showed a higher amount of cell toxicity and apoptosis compared to respective controls. Expression of anti-apoptotic protein (B-cell lymphoma-extra-large) was downregulated and cleavage of poly (ADP-ribose) polymerase, a marker of apoptosis was higher in cells treated with doxorubicin (2 μg/mL) and 131 I-rituximab (P ≤ 0.05). Moreover, in these cells the basal level of expression of p42/44 and p38 were increased while its phosphorylation was decreased.

CONCLUSION

These results suggest that doxorubicin has the potential to sensitize (131)I-rituximab induced cell death in Raji cells.

Lead finding for acetyl cholinesterase inhibitors from natural origin: structure activity relationship and scope

Acetylcholinesterase (AChE) inhibitors are considered as promising therapeutic agents for the treatment of several neurological disorders such as Alzheimer's disease (AD), senile dementia, ataxia and myasthenia gravis. There are only few synthetic medicines with adverse effects, available for treatment of cognitive dysfunction and memory loss associated with these diseases. A variety of plants has been reported to possess AChE inhibitory activity and so may be relevant to the treatment of neurodegenerative disorders such as AD. Hence, developing potential AChE inhibitors from botanicals is the need of the day. This review will cover some of the promising acetylcholinesterase inhibitors isolated from plants with proven in vitro and in vivo activities with concern to their structure activity relationship.

5-Ethyl-2-(4-fluoro-phen-yl)-4-phen-oxy-1H-pyrazol-3(2H)-one

In the title compound, C₁₇H₁₅FN₂O₂, the essentially planar pyrazole ring [maximum deviation = 0.026 (1) Å] makes dihedral angles of 72.06 (7) and 33.05 (7)°, with the phenyl and fluoro­benzene rings, respectively. The dihedral angle between the two six-membered rings is 87.88 (7)°. In the crystal, inter­molecular N—H⋯O and C—H⋯F hydrogen bonds link the mol­ecules into layers lying parallel to the bc plane.

5-Ethyl-4-phenyl-1H-pyrazol-3(2H)-one

The asymmetric unit of the title compound, C(11)H(12)N(2)O, consists of two crystallographically independent mol-ecules (A and B) with similar geometries. Both mol-ecules exist in a keto form, the C=O bond length being 1.286 (2) Å in A and 1.283 (2) Å in B. The dihedral angles between the pyrazole ring and the attached phenyl ring are 43.28 (12) and 46.88 (11)°, respectively, for A and B. The ethyl unit in mol-ecule B is disordered over two positions with a site-occupancy ratio of 0.508 (5):0.492 (5). In the crystal, each of the independent mol-ecules forms a centrosymmetric dimer with an R(2) (2)(8) ring motif through a pair of N-H⋯O hydrogen bonds. These dimers are further connected into a three-dimensional network by inter-molecular N-H⋯O and C-H⋯O hydrogen bonds. Inter-molecular C-H⋯π inter-actions are also present.

Generic antibiotic industries: Challenges and implied strategies with regulatory perspectives

Ever since the discovery of antibiotics, the quality of human life greatly improved in the 20(th) century. The discovery of penicillin transformed the medicine industry and initiated a search for a better antibiotic every time resulting in several synthetic and semi-synthetic antibiotics. Beginning with the 1937 sulfa drug tragedy, the drug regulations had a parallel growth along with the antibiotics and the antibiotic-based generic Pharma industries. This review article is focused on the scenario depicting current global Pharma industries based on generic antibiotics. Several regulatory aspects involved with these industries have been discussed along with the complexity of the market, issues that could affect their growth, their struggle for quality, and their compliance with the tightened regulations. With the skyrocketing commercialization of antibiotics through generics and the leveraging technologic renaissance, generic industries are involved in providing maximum safer benefits for the welfare of the people, highlighting its need today..

1-{[5-(4-Chloro-phen-yl)-1-(4-fluoro-phen-yl)-1H-pyrazol-3-yl]carbon-yl]}piperidin-4-one

In the title compound, C(21)H(17)ClFN(3)O(2), the 1H-pyrazole ring makes dihedral angles of 36.73 (7), 18.73 (7) and 60.88 (8)°, respectively, with the mean planes of the chloro-phenyl, 4-oxo-piperidine and fluoro-phenyl rings. The mol-ecular structure is stabilized by an intra-molecular C-H⋯N hydrogen bond, which forms an S(6) ring motif. In the crystal, inter-molecular C-H⋯O hydrogen bonds link mol-ecules into chains along [101]. In addition, inter-molecular C-H⋯F hydrogen bonds with an R(2) (1)(7) ring motif connect neighbouring chains into layers parallel to the ac plane.

5-Isobutyl-4-phenyl-sulfonyl-1H-pyrazol-3(2H)-one

The title compound, C₁₃H₁₆N₂O₃S, consists of two crystallographically independent mol­ecules with similar geometries and exists in a keto form, the C=O bond lengths being 1.267 (2) and 1.254 (2) Å. In both mol­ecules, the pyrazole rings are approximately planar, with maximum deviations of 0.017 (2) and 0.010 (2) Å, and the dihedral angles between the pyrazole and phenyl rings are 83.63 (11) and 70.07 (12)°. In one mol­ecule, an intra­molecular C—H⋯O hydrogen bond with an S(6) ring motif is observed. In the crystal, inter­molecular N—H⋯O and C—H⋯O hydrogen bonds link the mol­ecules into two-dimensional networks parallel to the ab plane.

1-(4-Fluoro-phen-yl)-3-methyl-4-phenyl-sulfanyl-1H-pyrazol-5(4H)-one

The title compound, C₁₆H₁₃FN₂OS, has undergone enol-to-keto tautomerism during the crystallization process. The 1H-pyrazole-5-one ring [maximum deviation = 0.0198 (11) Å] is inclined at angles of 33.10 (5) and 79.57 (5)° with respect to the fluoro­phenyl [maximum deviation = 0.0090 (12) Å] and phenyl­thiol [maximum deviation = 0.0229 (3) Å] rings attached to it. In the crystal, neighbouring mol­ecules are linked into inversion dimers, generating R₂²(8) ring motifs. These dimers are further linked into two-dimensional arrays parallel to the bc plane via inter­molecular N—H⋯O, C—H⋯F and C—H⋯O hydrogen bonds. The crystal is further stabilized by weak π–π [centroid–centroid distance = 3.6921 (7) Å] and C—H⋯π inter­actions.

4-{[5-(4-Chloro-phen-yl)-1-(4-fluoro-phen-yl)-1H-pyrazol-3-yl]carbon-yl}-N-(4-cyano-phen-yl)piperazine-1-carboxamide

In the title compound, C(28)H(22)ClFN(6)O(2), the piperazine ring adopts a chair conformation and the least-squares plane through the four coplanar atoms forms dihedral angles of 69.37 (13) and 56.56 (12)°, respectively, with the pyrazole and cyano-phenyl rings. The dihedral angles formed between the pyrazole and the attached fluoro- and chloro-phenyl rings are 34.16 (10) and 73.27 (12)°, respectively. In the crystal, inter-molecular N-H⋯O, C-H⋯N and C-H⋯O hydrogen bonds link the mol-ecules into sheets parallel to the ac plane.

Bioevaluation of radioactive bandages in a murine model of melanoma

PURPOSE

To study the effectiveness of a radioactive bandage incorporating a beta(-) emitter for the treatment of superficial tumours like melanoma.

MATERIALS AND METHODS

(188)Re tin particles were immobilized on a bandage patch ((188)Re bandage). The effectiveness of the (188)Re bandage for controlling tumour growth was tested in C57BL/6 mice bearing BL6/FIO melanoma. The effect of the single dose delivered, two-dose treatment and time of contact of bandages on the skin was studied by following tumour size.

RESULTS

Tumour growth was delayed significantly in treated animals compared with controls. Complete tumour regression was observed with some doses of radiation. Histology studies and dose-rate calculations were also carried out to evaluate the effectiveness of (188)Re bandages.

CONCLUSIONS

Radioactive bandages could be a promising modality for the treatment of skin cancers.

Preparation and preliminary biological evaluation of a novel 109Pd labeled porphyrin derivative for possible use in targeted tumor therapy

AIM

The labeling of a porphyrin, a tumor-avid agent, with a beta-emitting radionuclide for evaluating its potential as an agent for targeted tumor therapy is reported. A novel water soluble porphyrin viz. 5,10,15,20-tetrakis[3,4-bis(carboxymethyleneoxy)phenyl]porphyrin radiolabeled with(109)Pd (E(beta(max))=1.12 MeV, Eg=88 keV (3.6%), T1/2=13.7 h) has been prepared. The designing of this agent is based on the speculation that (109)Pd would complex with the tetrapyrrole donor array constituting the porphyrin core, resulting in a species with peripheral hydrophilic residues for facilitating renal excretion.

METHODS

Palladium-109 was produced by thermal neutron bombardment on enriched metallic Pd target at a flux of 3 x 10(13) n/cm(2) x s for 3 days and the porphyrin derivative was synthesized by a multi-step reaction using 3,4 dihydroxybenzaldehyde and pyrrole. The labeling parameters were optimized for obtaining maximum complexation yield and the biological behavior of the radiolabeled porphyrin was studied in Swiss mice bearing fibrosarcoma tumors.

RESULTS

Palladium-109 was produced with a specific activity of approximately 1.85 GBq/mg and approximately 100% radionuclidic purity. Lead-109 complex of the synthesized porphyrin derivative was prepared with excellent radiochemical purity (approximately 98%) and the complex was observed to be stable upto 24 h at room temperature. Results of the biodistribution studies revealed good tumor uptake (2.8+/-0.57%/g) within 30 min post-injection and it remained almost constant till 24 h post-injection. The complex showed predominantly renal clearance (88.68+/-4.01% at 24 h post-injection).

CONCLUSIONS

The high tumor/blood and tumor/muscle ratios (4.36 and 38 at 24 h post-injection) exhibited by the radiolabeled porphyrin indicate its potential for using in targeted tumor therapy.

A toxicological evaluation of 2-dimethylaminomethyl-1-phenyl-2-propen-1-one hydrochloride

2-Dimethylaminomethyl-1-phenyl-2-propen-1-one hydrochloride (3) is a novel cytotoxic and anticancer agent. The objective of this study was to obtain information pertaining to possible toxic symptoms detected by in vivo evaluations in mice and an in vitro test for mutagenicity. The data obtained revealed that 3 had no effect on alanine transaminase, aspartate transaminase, HDL cholesterol and protein concentrations in sera nor were variations in the numbers of red and white blood cells detected. Furthermore autopsies of treated mice revealed no pathological symptoms in the heart, kidney, brain, spleen and testes. However elevation of the concentrations of total cholesterol, triglycerides, creatinine and urea were noted in treated mice as well as inflammation of the liver and lungs. Chromosomal aberrations were detected in a micronuclei test. In the Ames test, compound 3 was converted into one or more mutagens in the presence (but not the absence) of a murine liver homogenate. Thus future molecular modifications of 3 should bear in mind approaches to reduce or minimize unwanted side effects.

Optimization and performance evaluation of peptide-loaded monolithic poly-epsilon-caprolactone microspheres in mice bearing melanoma B16F1

The objective of this investigation was to develop a bleomycin depot based on monolithic microparticulate technology to suppress tumour growth and to maintain constant plasma drug concentrations within an optimal therapeutic window over a prolonged period of time. Formulations were optimized with biodegradable poly-epsilon-carpolactone and evaluated in vitro for physicochemical characteristics, drug release in phosphate buffered saline (pH 7.4) and evaluated in vivo in tumour bearing mice. This investigation revealed that upon subcutaneous injection, the biodegradable depot-forming poly-epsilon-carpolactone microspheres controlled drug release and suppressed tumour growth kinetics significantly compared to control. A preliminary pharmacokinetic evaluation exhibited steady plasma drug concentrations during the study period. This formulation with its reduced frequency of administration and better control of drug disposition is expected to provide an economic benefit to the user compared with products currently available for chemotherapy.

Preparation and evaluation of 90 Y skin patches for therapy of superficial tumours in mice

90Y, a beta emitting radionuclide, was immobilized in a bandage patch for possible application for the therapy of superficial maladies such as tumours and skin cancers. The aim was to prepare a radiation source that could deliver uniform dose within a short duration and avoid the inconveniences faced with the gamma sources used in teletherapy and brachytherapy. 90Y-ferric hydroxide macroaggregates were prepared, filtered and immobilized between two layers of gauze. When placed in saline, no radioactivity leached for 3 days, proving its safety for external application. Fibrosarcoma was induced in mice for checking the efficacy of 90Y patches. 90Y patches of various activities were prepared and applied on the tumours. The effect of time gap between inception and treatment of tumour, dose delivered and multiple application in fractionated doses was studied. In all the cases, tumour growth in the treated animals was considerably reduced in comparison with controls. It was concluded from the experiments that treatment should be started at the earliest stage possible, i.e. when the tumour is palpable. Delivery of dose from radioactive patches of approximately 90-100 MBq each, thrice at weekly intervals proved to be more effective for regression of tumour growth.

177Lu labelled polyaminophosphonates as potential agents for bone pain palliation

Polyphosphonate ligands labelled with radioisotopes decaying by moderate energy beta emission have shown utility as palliative agents for painful bone metastasis. 177Lu (T(1/2)=6.71 d, Ebetamax=497 keV) has radionuclidic properties suitable for use in palliative therapy of bone metastasis. 177Lu was produced at a high specific activity and excellent radionuclidic purity by thermal neutron bombardment of a target prepared from natural Lu. Three polyaminomethylene phosphonate ligands, abbreviated as EDTMP, DTPMP and TTHMP, were synthesized and radiolabelled with 177Lu. Complexation parameters were optimized to achieve maximum yields (97-99.5%). All the complexes were found to retain their stability at room temperature even 14 days after preparation. Biodistribution studies of the complexes were carried out in Wistar rats. All the complexes showed significant bone uptake (6-6.5%/g in tibia at 3 h post-injection (p.i.)) with rapid clearance from blood and minimum uptake in soft tissues. These studies reveal that 177Lu complexes with the synthesized ligands have a potential use in palliative treatment of painful bone metastasis.

A novel [186/188Re]-labelled porphyrin for targeted radiotherapy

The concept of labelling a porphyrin, a tumour-avid agent, with a radionuclide to evaluate its potential as a therapeutic modality is reported. A novel water-soluble porphyrin, namely meso-tetrakis[3,4-bis(carboxymethyleneoxy)phenyl]porphyrin, with suitable dicarboxylic acid groups as aromatic substituents in the periphery, was synthesized and characterized. The labelling of this porphyrin with 186/188Re, a beta(-) emitter, was optimized by varying the reaction conditions. The complexation yield was >98% as estimated by paper chromatography in acetone and in saline. The radiochemical purity was found to remain at >98% when stored at 4 degrees C for 24 h. Biodistribution studies in Swiss mice bearing fibrosarcomas showed an uptake of approximately 3.5% per gram of tumour at 30 min post-injection. This uptake in the tumour was retained until 24 h post-injection with major activity showing renal clearance; no significant activity was present in other organs of interest. The tumour/blood and tumour/muscle ratios were observed to be 38 and 5, respectively, at 24 h post-injection, thereby indicating a possible therapeutic potential for tumours.

Radiolabelled monoclonal antibodies against human cardiac myosin

Myocardial infarction (MI) can be monitored using several protein markers including human cardiac myosin (HCM). Monoclonal antibodies were raised against HCM by hybridoma technique. Antimyosin antibody producing clones were identified by ELISA and monoclonality was established by limiting dilution. The antibodies were purified, isotyped and their cross reactions with myosin from other species were estimated. All the clones showed negligible cross reaction with rabbit myosin, but reacted with bovine skeletal myosin to different extents (40-100%). The most avid antibody Mab 4G4 which also strongly reacted with rat cardiac myosin, was labelled with 125I using different oxidising agents such as iodogen, chloramine-T and lactoperoxidase. More than 95% pure radiolabelled antibody could be obtained by gel filtration. The immunoreactivity was retained. Mab 4G4 was also labelled with 99mTc using stannous tartrate as the reducing agent. Radiolabelling yield was approximately 60%, the purity was >95%. Both the radiolabelled preparations were tested for biodistribution in rats--both normal and those with induced MI. Approximately 0.7 % of the injected activity/g was found in the infarcted region and the accumulation of activity in the infarcted heart was 1.5 times that in the normal heart. A very high percentage of activity (80%) accumulated in the thyroid. With further optimisation of labelling and use of F(ab')2 fragments, better delineation of the infarct sites may become possible.

A slotted waveguide applicator for continuous flow grain drying

A slotted waveguide antenna was designed and developed with series slots cut on the broad side that constituted a popular means of coupling microwaves with grain for drying. The radiating characteristics of the slotted wave guide antenna mounted in a setup that simulated the coupling to a grain conveying tube were studied at a frequency of 2.45 GHz. The antenna consisted of a WR-340 waveguide made of copper. The effect of the slot inclination angle O, moisture content and the shape of the slots were investigated. The results indicated 55 degrees as an optimum slot angle for slots having a width of 13 mm and a length 58 mm. Slots with a width of 6 mm did not exhibit any regular behavior and the effect of O was not clearly identified.