Interplay of Anisotropy Energy Barrier and Self-Heating Efficiency of Cobalt-Substituted CuFe2O4 Nanoparticles.

In this study, we delve into the intricate interplay between the anisotropy energy barrier and the self-heating efficiency of magnetic nanoparticles (MNPs). We embarked on this exploration by synthesizing Cu1-xCoxFe2O4 (x = 0, 0.1, 0.3, and 0.5) MNPs using a straightforward coprecipitation method. Our magnetic assessments, conducted at different temperatures, unveiled a notable trend as we traversed from x = 0.1 to x = 0.5. Specifically, we observed a consistent increase in saturation magnetization, coercivity, and remanence. This pattern also extended to the anisotropy energy barrier, which was derived from the effective anisotropy constant determined through the temperature dependency of the coercivity method. However, an intriguing twist emerged when we scrutinized the specific absorption rate (SAR), calculated via the Box-Lucas method. Contrary to much of the existing literature, our experimental results showcased a decline in SAR concerning x. This experimental work challenges the conventional understanding of the relationship between the anisotropy energy barrier and the SAR value of these nanoparticles. This study prompts us to reconsider the intricate mechanisms governing the relaxation of magnetic moments and subsequent heat release when subjected to an alternating magnetic field. By doing so, we aim to gain fresh insights into the self-heating properties of MNPs and optimize their utilization to better understand their heat-release properties and ensure that they are used as efficiently as possible in a variety of biomedical applications.

Exploring Optically Stable Reddish-Orange Fluorescent Magnetic Pigment (0.90)Y2O3:(0.10-x)Eu3+:(x)Bi3+ for Anti-counterfeiting Applications.

The (0.90)Y2O3:(0.10-x)Eu3+:(x)Bi3+ nanophosphors (0.00 ≤ x ≤ 0.06) are synthesised using chemical combustion citrate route and characterized via X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, UV- visible and photoluminescence spectroscopy. The scanning electron micrographs indicate that the grain size of the phosphors ranges between 40 to 50 nm. The photoluminescence (PL) spectra, acquired under the excitation wavelength of 365 nm of ultraviolet light, show emission peaks at wavelengths 580 nm, 586-598 nm, 610 nm, 629-661 nm and 686-695 nm corresponding to the 5D0 → 7FJ electronic transitions of the Eu3+ ion with J = 0, 1, 2, 3 and 4, respectively. The most intense PL spectra at 611 nm (5D0 → 7F2), showcasing reddish-orange emission, indicate a higher concentration of Eu3+ ions in asymmetric sites within the Y2O3 host matrix. The presence of the distinct electronic transitions of Eu3+ in PL spectra acclaims that Bi3+ ions transfer their energy efficiently to Eu3+ ions in the matrix. Physical and chemical tests are being conducted on nanophosphors with Bi3+ substitutional doping of x = 0.02 and x = 0.04, both demonstrating intense PL emission. Magnetisation measurements suggest the soft magnetic nature of the nanophosphors, attributing it to the presence of Eu3+ ions in the 7F2 state. The highest PL intensity is seen in the nanophosphor (x = 0.04) with substitutional doping of 6% of Eu3+ and 4% of Bi3+ in Y2O3. This nanophosphor also demonstrates excellent optical stability in the investigated conditions and exhibits soft magnetic behaviour, positioning it as a promising material for incorporation as a fluorescent magnetic pigment in security ink applications. These features serve to prevent counterfeiting of secured documents both optically and magnetically.

Structural phase transition driven dielectric and optical properties with reduction in band gap in Sr2+modified BaTiO3ceramics.

Ferroelectric materials with crystal symmetry transition from single phase to multiphase coexistence exhibit anomalous photosensitive properties. The optical properties (optical band gap and photosensitive) found on non-centrosymmetric and centrosymmetric systems achieved research interest because of their interesting behavior. In this regard, the lead-free polycrystalline Ba1-xSrxTiO3(BSTO, 0⩽x⩽0.3) has been synthesized to explore its crystal structure, dielectric, light absorption, and photocurrent sensing properties for various applications. Both experimental and theoretical studies on BSTO (0⩽x⩽0.3) ceramics confirm the crystal symmetry transition with the reduction of band gap as compared to pristine BaTiO3. This crystal symmetry transition plays an important role in varying the various physical properties as it involves the transition from the polar phase to the non-polar phase. The optical band gap has been estimated experimentally by the Tauc plot method and found that there is a small variation of energy band gap from 3.615 eV to 3.212 eV with Sr substitution. The highest dielectric constant was found to be 5327 at lower frequency on Ba0.76Sr0.24TiO3after that for further increase in Sr concentration the dielectric constant decreases because of the introduction of the non-polar phase. A strong correlation between crystal structure and physical properties (dielectric, optical, etc.) has been observed. The photocurrent of the samples is significant which reveals that the sample is influenced by the photons. In a nutshell, the present study deepens the understanding of the correlation between crystal structure and various physical properties of BSTO and, hence provides an idea of required design parameters to construct a ferroelectric system for better photosensitive nature suitable for device applications.

An exhaustive scrutiny to amplify the heating prospects by devising a core@shell nanostructure for constructive magnetic hyperthermia applications.

An interfacial integration at the nanoscale domain through a core@shell (CS) nanostructure has constructively unbarred a wide dimension to researchers on biomedical applications, especially for magnetic fluid hyperthermia. Lately, the interconnection of the exchange bias effect (EBE) through the interface coupling to the magnetic heating efficiency has uttered its utmost prominence for researchers. Here, we delineate the ascendency of the heating ability through a coalescing assembly of mixed ferrite Co0.5Zn0.5 Fe2O4 (CZ) and soft magnetic material Fe3O4 (F), by devising a network of CoZnFe2O4@Fe3O4 (CZF) CS nanostructure. A hefty interface activity with validation of the EBE phenomenon is divulged through magnetic scrutiny for the CS sample. The magnetic nanoparticles heating response to applied magnetic field and frequency is discerned at three distinct fields, where the outcome prevailed to inflated specific loss power for CS CZF in distinction to bare F and CZ samples for all the assessments. Remarkably; a lofty intrinsic loss parameter is also perceived for the CS sample recorded to about 5.36 nHm2 g-1; which is another eccentric outcome that significantly labels the CS CZF sample as a potentially high heating competence agent. This comprehension accords to a finer perspective to meliorate the theranostic environment for hyperthermia applications.

A new type low-cost, flexible and wearable tertiary nanocomposite sensor for room temperature hydrogen gas sensing.

This paper reports on reduced graphene oxide (rGO), tin oxide (SnO2) and polyvinylidene fluoride (PVDF) tertiary nanocomposite thick film based flexible gas sensor. The nanocomposite of 0.90(PVDF) - 0.10[x(SnO2) - (1 - x)rGO] with different weight percentages (x = 0, 0.15, 0.30, 0.45, 0.6, 0.75, 0.90 and 1) have been prepared by the hot press method. Chromium (Cr) has been deposited on the surface by using E-beam evaporation system, which is used as electrode of the device. Crystal structure, morphology, and electrical characteristics of the device have been explored for the technological application. A correlation between crystallinity, morphology, and electrical properties with these thick films has also been established. The device has been tested at different hydrogen (H2) gas concentration as well as at different response times. A superior response of 0.90(PVDF) - 0.10[0.75(SnO2) - 0.25 rGO] nanocomposite thick film has been observed. Hence, this composition is considered as optimized tertiary nanocomposite for the hydrogen gas sensor application. The sensor response of 49.2 and 71.4% with response time 34 sec and 52 sec for 100 PPM and 1000 PPM H2 gas concentration respectively have been obtained. First time a new kind of low cost and flexible polymer based nanocomposite thick film gas sensor has been explored.

Surgical Management of Peptic Perforation in a Tertiary Care Center: A Retrospective Study.

BACKGROUND: The purpose of this study is to estimate disease burden, clinical features, and outcome in the emergency surgical management of peptic perforation in a rural government tertiary care center where patients are socioeconomically very poor and also impacted by lack of good quality health-care facility. MATERIALS AND METHODS: The study had retrospectively analyzed 121 patients with peptic perforation who had undergone emergency laparotomy at Midnapore medical college, West Bengal, India, from June 2018 to December 2019. All patients >12 years were included in this study. Exclusion criteria were other traumatic and nontraumatic gastrointestinal perforations. RESULTS: The study population had 112 males and 9 females with a mean age of 44.80 ± 15.29 years and maximum incidence in the 6th decade (P = 0.001). Smoking and alcohol were associated with 54.5% and 49.6%, respectively. The symptoms were pain abdomen (100%) with vomiting (38.8%) and fever (33.9%). The signs of hypotension, peritonitis, distension, and pneumoperitoneum were observed in 34.7%, 64.5%, 39.7%, and 83.5%, respectively. Only 20.7% of patients were admitted within the first 24 h. The mean duration of symptoms was 2.3 days. Most perforations were located on the duodenum (74.4%) with duodenal to gastric perforation ratio 2.9:1. The mean size was 1.02 cm. Chest infection (19%) was the most common complication. The mortality rate was 9.1%. The mean length of hospital stay was 11.1 days. CONCLUSION: Peptic perforation remains a major disease burden in our environment predominantly due to late presentation, leading to high morbidity and mortality.

Nonstoichiometric charge defect induced relaxor antiferroelectric ordering in La modified Bi0.5 (Na0.80K0.20)0.5TiO3 relaxor ferroelectric.

The effect of A-site nonstoichiometric in La3+ modified Bi0.5(Na0.80K0.20)0.5TiO3/BNKT solid solution on crystal structure and electrical properties have been investigated. Evolution of crystal structure from rhombohedral (R3c) to tetragonal (P4bm) symmetry with reduction of the lattice distortion has been observed. The Raman spectra analysis is well supported to the crystal structure study from the XRD patterns analysis. The presence of charge defects due to non-stoichiometric composition and the reduction of oxygen vacancies have been confirmed by the x-ray photoelectron spectra (XPS) of the respective elements. The FESEM (field emission scanning electron microscopy) micrographs clearly show the reduction of grain size with the incorporation of La3+ in A-site of BNKT. The multiple dielectric anomalies near depolarization temperature (T d) and temperature at maximum dielectric value (T m) in the temperature dependent dielectric curves ascribe the diffuse phase transition with relaxor ferroelectric nature. The dielectric anomalies at T d and T m become more pronounce with the increase in addition of La3+ into BNKT lattice. The presence of charge defects with A-sites complexity leads to interrupt the long range polar ferroelectric domains and, forms the polar nanoregions (PNRs). The competition between ferroelectric R3c symmetry and non-polar P4bm symmetry with the addition of La3+ into the BNKT lattice induces an intermediate modulated phase, which exhibits the antiferroelectric in nature having pinched ferroelectric hysteresis loop.

Study on physical properties of Ayurvedic nanocrystalline Tamra Bhasma by employing modern scientific tools.

BACKGROUND: Tamra Bhasma is derived from metallic copper that is recommended for different ailments of liver and spleen, dropsy, abdominal pain, heart disease, colitis, tumors, anemia, loss of appetite, tuberculosis, as well as eye problems. OBJECTIVES: The knowledge of crystallite size and active ingredients in Bhasma materials is limited restricting its use as nanomedicine in the modern era. Also, the 2015 Nobel prize in medicine has motivated many researchers towards traditional medicines. Therefore, the different chemical and physical properties of prepared Tamra Bhasma has been studied by modern experimental tools (XRD, VSM, SEM, FTIR and PL spectrometer) and the preliminary testing of Tamra Bhasma nanoparticles was examined on bacteria. MATERIALS AND METHODS: Bhasma is prepared by metals and minerals using three step procedures e.g. Shodhana, Bhavana and Marana. In the present work, for the preparation of Tamra Bhasma, pulverized copper wire was used and prepared by the principle of Puta (incineration) in an Electrical Muffle Furnace (EMF). RESULTS: X-ray diffraction analysis and scanning electron microscopy results revealed that the crystallite size of Bhasma powder was less than 100 nm and nanocrystallites of aglomerated size in micrometer. Magnetometer measurement supports its medicinal value. Photoluminescence (PL) properties of nanocrystalline Bhasma powder was investigated in UV-NIR region and shows luminescence in visible region. The antimicrobial study of Tamra Bhasma shows effectiveness on bacteria and, may be useful to control the bacterial infection disease. CONCLUSION: Scientific data obtained using modern scientific tools and evidence would support in utilizing the ancient Indian wisdom of Ayurveda for the development of newer drugs as a modern nanomedicine and in other possible technological applications.

Conventional Laparoscopic Appendicectomy and Laparoscope-Assisted Appendicectomy: a Comparative Study.

Laparoscopic procedures for removal of the appendix by the three-port technique as an alternative to conventional appendicectomy have gained wide popularity, but they have been criticized for technical difficulty, more time consumption, and high cost. We have compared conventional three-port laparoscopic appendicectomy (LA) and laparoscope-assisted appendicectomy (LAA). In period from August 2010 to January 2012, 77 patients underwent appendicectomy by a minimally invasive procedure (39 LA and 38 LAA), at Medical College and Hospital, Kolkata. All the 39 cases of LA were completed successfully, but of the 38 cases, LAA could be completed only in 32 cases. Of the six cases where LAA could not be completed, five were converted to LA [three because of excessive body mass index (BMI) and two because of bleeding]. One case had to be converted to open appendicectomy because of excessive bleeding. In LA, the mean duration of surgery was less than that in LAA (18.18 versus 24.39 min). Wound infections were more common in LAA compared to LA (six versus two). Severe postoperative pain was present in eight cases in LAA compared to two in LA. On day 2, 79.487 % patients undergoing LA were discharged compared to 28.947 % in LAA. LA is better as a minimally invasive procedure. LAA can only be done in patients with lower BMI, is more time consuming, has more complications, more incidence of postoperative pain, wound infections, and longer hospital stay.

Transinguinal preperitoneal technique of inguinal hernioplasty - a better alternative to lichtenstein procedure.

INTRODUCTION: The Lichtenstein technique is currently one of the popular methods in practice as it provides very good results consistently. However many patients suffer from wound indurations' and chronic wound pain which are often underreported. The transinguinal preperitoneal technique (TPT) avoids these complications by placing the mesh in preperitoneal plane by open approach. MATERIALS AND METHODS: In this study, 71 patients were randomized into two groups one, of which one underwent the Lichtenstein repair and the other preperitoneal repair by TPT. All the patients were followed up for two years. RESULTS: Patients in TPT group had less pain in immediate post-operative period (p - .005), less wound induration and chronic pain on follow-up. Patients were also able to return to work early (p =0.036) . Average duration of operation was slightly longer compared to Lichtenstein technique (p < .0061) .There was no recurrence in either group on 2 year follow-up. CONCLUSION: This study shows that TPT provides a better alternative to Lichtenstein technique with decreased incidence of wound complications and chronic groin pain, while having a similar recurrence rate. Preperitoneal mesh placement by open approach in TPT is also easier and eliminates the need for laparoscopy.

Bilateral temporalis muscle hypertrophy--two case reports.

Isolated idiopathic bilateral temporalis muscle hypertrophy is a very rare clinical entity. It can change the facial appearance that manifests itself as a morphopsychological conflict for the subject, which is termed as 'Minotaur syndrome' in the medical literature. Here one such case is reported. The second patient sought medical attention for fear of malignancy.

Primary tuberculosis of the glans penis.

Primary Tuberculosis of penis is an extremely rare entity, even in the developing countries. We report a case of a 31 years old male patient who presented to us with some ulcerated lesions on the glans penis and was diagnosed as primary tuberculosis of glans penis, confirmed by biopsy and supported by a strongly positive Mantoux test and positive TB-PCR. The patient responded to anti- tubercular therapy well. There was no co-existing tuberculous infection elsewhere.

Primary Peritoneal Hydatidosis in a 76-Year-Old Farmer: An Unusual form of a Common Disease.

A 76-year-old farmer presented at our emergency unit with a history of gradual swelling of abdomen without fever, nausea, or urticaria. On examination there was symmetrical enlargement of abdomen with fluid thrill. Contrast-enhanced computed tomography scan showed that the entire peritoneal cavity was distended and occupied by multiloculated noncalcified content of mixed attenuations. Diagnosis of peritoneal seeding of hydatid cyst was made. At laparotomy, about 25 l of daughter cysts and a membrane was found in the peritoneal cavity without other organ involvement. Postoperative period was uneventful.

Experience of laparoscopic cholecystectomy under spinal anesthesia with low-pressure pneumoperitoneum--prospective study of 300 cases.

INTRODUCTION: Having long experience of open upper abdominal surgery under spinal anesthesia and laparoscopic cholecystectomy under general anesthesia, we performed this study of laparoscopic cholecystectomy with low-pressure pneumoperitoneum under spinal anesthesia to assess its safety and feasibility. MATERIALS AND METHODS: In a private rural health set-up, 300 patients were selected prospectively for laparoscopic cholecystectomy under low-pressure (8 mm) pneumoperitoneum under spinal anesthesia in a span of three years. Only 3.5 ml of 0.5% bupivacaine was used for spinal anesthesia. Fourth port positioned at lower than usual at the level of umbilicus, change of position of the table with different stages of operation, massaging of right shoulder in cases of shoulder pain, removal of smoke if formed during dissection to diminish shoulder pain and holding the body of the gallbladder by the fourth port grasper at the level of lower margin of the liver in cases of long gallbladder were some modifications of standard laparoscopic cholecystectomy made in this study. RESULTS: We successfully performed the operations in 291 patients without major complications. Four patients denied operation under spinal anesthesia. Spinal anesthesia was converted to general anesthesia in two patients due to severe shoulder pain. The operation was converted to open cholecystectomy in three patients. Mean age was 34.6 years (range 21-82 years). Mean BMI was -23.1 (range 20.8-28.3). Mean duration of operation was 39.6 min (range 18-78 min). Mean O 2 saturation was 97.6%. Mean peak respiratory rate was 23.4 (range 16-38). 90.08% patients complained of right shoulder pain--most of them managed by shoulder massage alone. All patients were satisfied on follow up. CONCLUSION: Laparoscopic cholecystectomy under spinal anesthesia with low-pressure pneumoperitoneum can be performed safely and satisfactorily without major complications by experienced surgeons.

An unusual presentation of primary splenic hydatid cyst.

The larval form of the parasite Echinococcus granulosus causes a hydatid cyst. The most common sites are liver and lungs. We present an unusual case of an isolated primary hydatid cyst of the spleen. In our case, ultrasonography images of the spleen were not suggestive of hydatid disease except a large cystic lesion. We proceeded to conservative splenectomy that detected hydatid cyst incidentally during operation. This issue is considered common in our geographical area. A high suspicion of this disease is justified in endemic regions. Moreover, medical treatment should precede and follow the surgical intervention.

Alteration in phosphate uptake potential of wheat plants co-cultivated with salicylic acid.

The phosphate uptake potential was significantly stimulated with low concentration of salicylic acid (SA). In one of the wheat cultivars (Triticum aestivum Var. Sonalika), 50 microM SA stimulated phosphate (PO(4)(3-)) uptake. At higher concentrations of SA (500 and 1000 microM), the rate of uptake was reduced. These findings underscore the light and dose-dependent biphasic action of SA: a low 50 microM stimulated, and high concentrations 500 and 1000 microM inhibited, PO(4)(3-) uptake.