Successful Treatment of Confirmed Naegleria fowleri Primary Amebic Meningoencephalitis.

Primary amebic meningoencephalitis caused by Naegleria fowleri is a rare but nearly always fatal parasitic infection of the brain. Globally, few survivors have been reported, and the disease has no specific treatment. We report a confirmed case in Pakistan in a 22-year-old man who survived after aggressive therapy.

Polymeric pH-Responsive Metal-Supramolecular Nanoparticles for Synergistic Chemo-Photothermal Therapy.

Stimuli-responsive drug delivery carriers, particularly those exhibiting pH sensitivity, have attracted significant scholarly interest due to their promising potential in anticancer therapeutic applications. This phenomenon can primarily be ascribed to the inherently acidic nature of tumor microenvironments. However, pH-responsive carriers frequently require the incorporation of functional groups or materials sensitive to pH changes. Given the pH-sensitive characteristics of metal coordination with natural small-molecule drugs, organometallic supramolecules present a facile and effective strategy for integrating pH-responsive behavior into these systems. Meanwhile, utilizing the natural compound luteolin in conjunction with iron ions (Fe3+) through the advanced engineering technique of flash nanoprecipitation (FNP) results in the synthesis of stable, highly loaded nanoparticles (NPs) exhibiting a supramolecular photothermal effect. Our experimental findings substantiate that the photothermal effect persists over time, even after the pH-responsive release phase has ended. Consequently, these polymeric pH-responsive metallic supramolecular nanoparticles integrate chemotherapy and photothermal therapy, creating a synergistic approach to cancer treatment. This bifunctional platform, which exhibits both pH-responsive and photothermal properties, presents a highly promising avenue for biomedical applications, particularly in the area of tumor therapies. Its dual function offers a potentially efficacious approach to tumor treatment.

Exploiting Temporal Features in Calculating Automated Morphological Properties of Spiky Nanoparticles Using Deep Learning.

Object segmentation in images is typically spatial and focuses on the spatial coherence of pixels. Nanoparticles in electron microscopy images are also segmented frame by frame, with subsequent morphological analysis. However, morphological analysis is inherently sequential, and a temporal regularity is evident in the process. In this study, we extend the spatially focused morphological analysis by incorporating a fusion of hard and soft inductive bias from sequential machine learning techniques to account for temporal relationships. Previously, spiky Au nanoparticles (Au-SNPs) in electron microscopy images were analyzed, and their morphological properties were automatically generated using a hourglass convolutional neural network architecture. In this study, recurrent layers are integrated to capture the natural, sequential growth of the particles. The network is trained with a spike-focused loss function. Continuous segmentation of the images explores the regressive relationships among natural growth features, generating morphological statistics of the nanoparticles. This study comprehensively evaluates the proposed approach by comparing the results of segmentation and morphological properties analysis, demonstrating its superiority over earlier methods.

Date palm-magnetized biochar for in-situ stabilization of toxic metals in mining-polluted soil: evaluation using single-step extraction methods and phytoavailability.

Mining activities provide a pathway for the entry and accumulation of various heavy metals in soil, which ultimately leads to severe environmental pollution. Utilization of various immobilizing agents could restore such contaminated soils. Therefore, in this study, date palm-derived biochars (BCs: produced at 300 °C, 500 °C and 700 °C) and magnetized biochars (MBCs) were employed to stabilize heavy metals (Cd, Pb, Cu and Zn) in mining polluted soil. Metal polluted soil was amended with BCs and MBCs at w/w ratio of 2% and cultivated with wheat (Triticum aestivum L.) in a greenhouse. After harvesting, dry and fresh biomass of plants were recorded. The soil and plant samples were collected, and the concentrations of heavy metals were measured after extracting with water, DTPA (diethylenetriaminepentaacetic acid), EDTA (ethylenediaminetetraacetic acid), and acetic acid. BCs and MBCs resulted in reduced metal availability and uptake, with higher fresh and dry biomass (>36%). MBCs showed maximum decrease (>70%) in uptake and shoot concentration of metals, as these reductions for Cd and Pb reached below the detection limits. Among all single-step extractions, the DTPA-extractable metals showed a significant positive correlation with shoot concentrations of tested metals. Thus, the synthesized BCs and MBCs could effectively be used for stabilizing heavy metals and improve plant productivity in multi-contaminated soils. However, future studies should focus on long term field trials to restore contaminated mining soils using modified biochars.

This study has demonstrated the performance of magnetized biochars for in-situ stabilization of toxic metals (Cd, Pb, Cu and Zn) in mining polluted soil by single extraction method. All the produced BCs and magnetized BCs showed great potential in immobilizing the metals and reducing their availability in soil, consequently decreasing their shoot concentration and plant uptake. Significant negative correlations were observed between soil pH and metal extraction from applied extraction methods such as water soluble, DTPA, and EDTA extractions. We found DTPA as a suitable extractant for investigating metal uptake in plant in multi-contaminated soils. Treatments with MBCs showed maximum decrease in plant uptake and concentration of studied metals. Thus, application of MBCs could efficiently immobilize soil heavy metals.

Radon concentration in spring water as an indicator of seismic activity: a case study of the Muzaffarabad Fault in Pakistan.

Radon and its progenies found in water indicate the existence of seismically active faults in the region. However, exposure to high levels of radon can also result in radiation-related health risks. This study focuses on radon-based active tectonic studies along the Muzaffarabad Fault in the core of the Hazara-Kashmir Syntaxis (HKS), NW Himalayas, Pakistan. In this study, spring water samples were collected along roadside of Jhelum Valley and in close proximity to the Muzaffarabad Fault in Pakistan using Radon Thoron Monitor (RTM1688-2). The results of the study showed that the radon concentrations in the water samples ranged from 1.895 to 17.097 Bq/l. The study found that the highest radon concentration was observed in the samples collected closest to the fault, while the lowest concentration was observed in the samples collected further away. The statistical analysis between the radon concentration and the distance from the fault showed a strong inverse relationship (R2=0.73). The study also found that 68% of the sampling sites had radon concentrations that exceeded the maximum contamination level (MCL) set by the US Environmental Protection Agency (EPA). The higher radon concentrations in the springs water suggest the probability of earthquake, which in turn poses potential health risks for the local population. The findings suggest that the measurement of radon concentration in water can be used as a tool for identifying seismically active faults in the region.

Role of doppler ultrasound in detecting vascular complications in recipients of living donor liver transplant (LDLT).

OBJECTIVE: To determine the role of Doppler ultrasound in the detection of vascular complications in recipients of living donor liver transplant, keeping contrast-enhanced computerised tomography of abdomen as the gold standard. METHODS: The retrospective study was conducted from February 16 to April 1, 2022, at the Pakistan Kidney and Liver Institute and Research Centre, Lahore, Pakistan, and comprised data of living donor liver transplant recipients who had undergone contrast-enhanced computerised tomography of abdomen within 24 hours of Doppler ultrasound between January 2021 and January 2022. For the diagnosis of hepatic vascular complications, the diagnostic values of Doppler ultrasound parameters were derived by correlating Doppler ultrasound findings with contrast-enhanced computerised tomography results. Data was analysed using SPSS 20. RESULTS: Of the 35 patients, 24(68.6%) were men and 11(31.4%) were women. The overall mean age was 45.86±13.8 years. For hepatic artery thrombosis, the use of Doppler ultrasound criteria yielded a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 100%, 96.6%, 83.3%, 100%, and 97.1% respectively. For hepatic artery stenosis, overall sensitivity, specificity, positive predictive value, negative predictive value and accuracy of Doppler ultrasound was 100%, 96.8%, 75%, 100% and 97.1% respectively. Doppler ultrasound parameters resulted in a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 100% each in detecting portal vein and hepatic venous outflow tract thrombosis. Overall, Doppler ultrasound sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy was found to be 100%, 88.8%, 89.4%, 100% and 94.2% respectively. CONCLUSIONS: Doppler ultrasound was adequate to document vascular complications after living donor liver transplant in majority of the cases with high accuracy and sensitivity.

Blood product transfusion practices in pediatric critically ill patients at a tertiary care hospital, Pakistan.

Objective: To determine the frequency of inappropriate blood product transfusions in pediatric critically ill patients. Methods: We collected data for this descriptive study from January to December 2020 at the Pediatric Intensive Care Unit (PICU) of Dr. RKMP Civil Hospital, Karachi. We included all patients one month to 12 years of age, admitted to pediatric intensive care unit and received any blood product transfusion. We reviewed their medical records and noted the demographic and clinical variables, type of blood product transfused with its indication and determined whether transfusion was appropriate or not, as per the standard guidelines and consensus recommendations. Results: Number of patients who were transfused was n=39, out of which females were 51.3%. Mean age of the patients was 49.0 months ±50.9 months. Total number of transfusions done were n=135, with most common blood product transfused being Fresh Frozen plasma (FFP) in 44.4%. A total of n=117 (86.66%) transfusion were appropriate as per the standard guidelines, while 18 (13.33%) were inappropriate (P-value <0.5). The most common indication of FFP transfusion was INR >2.0 in 51.6%, for Packed red cell transfusion was hemoglobin between 5 and 7 gm/dl in 35.5% and for Platelets was <20,000 with risk of bleeding in 36.6%. Conclusion: This study highlights the occurrence of inappropriate transfusions in critically ill pediatric patients. We need to reinforce the knowledge of our health care workers and display the guidelines in intensive care units.

Two-Dimensional Supramolecular Polymerization of DNA Amphiphiles is Driven by Sequence-Dependent DNA-Chromophore Interactions.

Two-dimensional (2D) assemblies of water-soluble block copolymers have been limited by a dearth of systematic studies that relate polymer structure to pathway mechanism and supramolecular morphology. Here, we employ sequence-defined triblock DNA amphiphiles for the supramolecular polymerization of free-standing DNA nanosheets in water. Our systematic modulation of amphiphile sequence shows the alkyl chain core forming a cell membrane-like structure and the distal π-stacking chromophore block folding back to interact with the hydrophilic DNA block on the nanosheet surface. This interaction is crucial to sheet formation, marked by a chiral "signature", and sensitive to DNA sequence, where nanosheets form with a mixed sequence, but not with a homogeneous poly(thymine) sequence. This work opens the possibility of forming well-ordered, bilayer-like assemblies using a single DNA amphiphile for applications in cell sensing, nucleic acid therapeutic delivery and enzyme arrays.

DNA Sequence and Length Dictate the Assembly of Nucleic Acid Block Copolymers.

The self-assembly of block copolymers is often rationalized by structure and microphase separation; pathways that diverge from this parameter space may provide new mechanisms of polymer assembly. Here, we show that the sequence and length of single-stranded DNA directly influence the self-assembly of sequence-defined DNA block copolymers. While increasing the length of DNA led to predictable changes in self-assembly, changing only the sequence of DNA produced three distinct structures: spherical micelles (spherical nucleic acids, SNAs) from flexible poly(thymine) DNA, fibers from semirigid mixed-sequence DNA, and networked superstructures from rigid poly(adenine) DNA. The secondary structure of poly(adenine) DNA strands drives a temperature-dependent polymerization and assembly mechanism: copolymers stored in an SNA reservoir form fibers after thermal activation, which then aggregate upon cooling to form interwoven networks. DNA is often used as a programming code that aids in nanostructure addressability and function. Here, we show that the inherent physical and chemical properties of single-stranded DNA sequences also make them an ideal material to direct self-assembled morphologies and select for new methods of supramolecular polymerization.

Nanosecond Laser Induced Surface Structuring of Cadmium after Ablation in Air and Propanol Ambient.

In the present study KrF Excimer laser has been employed to irradiate the Cadmium (Cd) targets for various number of laser pulses of 500, 1000, 1500 and 2000, at constant fluence of 3.6 J cm-2. Scanning Electron Microscopy (SEM) analysis was utilized to reveal the formation of laser induced nano/micro structures on the irradiated target (Cd) surfaces. SEM results show the generation of cavities, cracks, micro/nano wires/rods, wrinkles along with re-deposited particles during irradiation in air, whereas subsurface boiling, pores, cavities and Laser Induced Periodic Surface Structures (LIPSS) on the inner walls of cavities are revealed at the central ablated area after irradiation in propanol. The ablated volume and depth of ablated region on irradiated Cd targets are evaluated for various number of pulses and is higher in air as compared to propanol ambient. Fast Fourier Transform Infrared spectroscopy (FTIR), Energy Dispersive X-ray Spectroscopy (EDS) and X-ray Diffraction (XRD) analyses show the presence of oxides and hydro-oxides of Cd after irradiation in propanol, whereas the existence of oxides is observed after irradiation in air ambient. Nano-hardness tester was used to investigate mechanical modifications of ablated Cd. It reveals an increase in hardness after irradiation which is more pronounced in propanol as compared to air.

Comparison of intra-cuff lidocaine vs alkalinized lidocaine effects for prevention of post-operative sore throat.

OBJECTIVE: To compare the effect of intra-cuff lidocaine versus alkalinized lidocaine in the prevention of post-operative sore throat. Methods: The cross-sectional study was conducted from June 15 to July 15, 2019, at the Department of Anaesthesiology, Liaquat National Hospital and Medical College, Karachi, and comprised patients of either gender aged 15-50 years classified as American Society of Anaesthesiologist class 1-2 and undergoing general anaesthesia with endotracheal intubation expected to last more than one hour. The patients were randomised into Group L and Group LA. General anaesthesia was given using induction dose of propofol 2-3mg/kg, nalbuphine 0.1mg/kg and atracurium 0.5mg/kg and female patients were intubated with 7.0mm size endotracheal tube and males patients with 8.0mm. All intubations were performed by an anaesthesiologist with minimum of two-year experience. The endotracheal tube cuff was inflated by using plain lidocaine 2% in group L and 2% lidocaine with 8.4% sodium bicarbonate in LA group till the air leak diminished. Post-surgery, the patients were assessed on extubation for any emergence phenomenon and were re-assessed at 1st, 6th, 12th and 24th hour. The assessment was done by the on-call anaesthesiology resident who was blinded to the study group. Data was collected using a proforma. The analysis was done using software IBM SPSS Statistics 23.0. Chi-Square Test was applied to analyse the data. RESULTS: Of the 58 patients, 33(56.9%) were male and 25(43.1%) were female. There were 26(44.8%) patients aged 25-36 years, while 12(20.7%) each were aged 36-45 years and 46-55 years. There were 29(50%) patients in each of the 2 groups. After 24 hours, 44(75.9%) patients in Group L did not complain of any pain, while in group LA the corresponding number was 56(96.6%). Both in terms of cough and hoarseness at 24 hours, 56(96.6%) patients in Group L did not have complaints, while in Group LA there were no such complaints. In Group L, heart rate 60-80 was noted in 20(69%) patients and 81-100 in 9(31%). In Group LA, the corresponding values were 17(58.6%) and 12(41.4%). Conclusion: Alkalinized lidocaine was found to be highly effective in preventing post-operative throat complications compared to lidocaine.

Does economic complexity matter for environmental sustainability? Using ecological footprint as an indicator.

The current decade has witnessed the rise of empirical research in the domain of ecological footprint which has become a major scholarly area among environmental researchers. However, many key factors determining ecological footprint have been inadequately dealt within the existing body of knowledge. The current research aims to explore the association between economic complexity, human capital, renewable energy generation, urbanization, economic growth, export quality, trade and ecological footprint for the top ten economic complex countries. This study applied panel data estimators, for instance, fully modified ordinary least squares (FMOLS), dynamic ordinary least squares (DOLS) and the system-GMM long-run estimators from 1980 to 2017. The long-run estimates reveal that economic complexity, economic growth, export quality, trade and urbanization increase ecological footprint. Human capital and renewable energy generation help to mitigate ecological footprint. We conclude that investment in more renewable energy generation and its consumption and efficient use of human capital will improve economic complexity, export quality, and environment in developed and developing countries.

Sulfamethoxazole Leaching from Manure-Amended Sandy Loam Soil as Affected by the Application of Jujube Wood Waste-Derived Biochar.

Vertical translocation/leaching of sulfamethoxazole (SMZ) through manure-amended sandy loam soil and significance of biochar application on SMZ retention were investigated in this study. Soil was filled in columns and amended with manure spiked with 13.75 mg kg-1 (S1), 27.5 mg kg-1 (S2), and 55 mg kg-1 (S3) of SMZ. Jujube (Ziziphus jujube L.) wood waste was transformed into biochar and mixed with S3 at 0.5% (S3-B1), 1.0% (S3-B2), and 2.0% (S3-B3) ratio. Cumulative SMZ leaching was lowest at pH 3.0, which increased by 16% and 34% at pH 5.0 and 7.0, respectively. A quicker release and translocation of SMZ from manure occurred during the initial 40 h, which gradually reduced over time. Intraparticle diffusion and Elovich kinetic models were the best fitted to leaching data. S3 exhibited the highest release and vertical translocation of SMZ, followed by S2, and S1; however, SMZ leaching was reduced by more than twofold in S3-B3. At pH 3.0, 2.0% biochar resulted in 99% reduction in SMZ leaching within 72 h, while 1.0% and 0.5% biochar applications reduced SMZ leaching to 99% within 120 and 144 h, respectively, in S3. The higher SMZ retention onto biochar could be due to electrostatic interactions, H-bonding, and π-π electron donor acceptor interactions.

Green synthesis of nickel oxide nanoparticles using Allium cepa peels for degradation of Congo red direct dye: an environmental remedial approach.

Direct dyes are used in different textile operations and processings. The textile industries are disposing of unused direct dyes into the aquatic environment which is posing a serious alarming threat to aquatic lives. The current study deals with the synthesis of nickel oxide nanoparticles using Allium cepa peels aqueous extract. Nickel oxide nanoparticles (NiO-NPs) were characterized by scanning electron microscopy (SEM). Synthesized NiO-NPs were used to remove Congo red direct dye. Various experimental factors like concentration of dye and nanoparticles, pH, and temperature were optimized. Congo red direct dye was decolorized up to 90% at optimized conditions (Congo Red Direct dye concentration 0.02%, catalyst dose 0.003 g·L-1, pH 6, and temperature 50 °C). The real textile industry effluent disclosed 70% decolorization at optimized conditions. The percent reduction in total organic carbon (TOC) and chemical oxygen demand (COD) was found to be 73.24% and 74.56% in the case of Congo red dye catalytic treatment and the percent reduction in TOC and COD was found to be 62.47% and 60.23%, respectively, in the treatment of textile effluent using nickel oxide nanoparticles as a catalyst. Treated and untreated dye samples were exposed to Fourier transform infrared (FTIR) and UV-Visible spectral analyses too. The reaction products were studied by degradation pathway.

P.arg102ser is a common Pde6a mutation causing autosomal recessive retinitis pigmentosa in Pakistani families.

OBJECTIVE: To explore the genetic cause of autosomal recessive retinitis pigmentosa in consanguineous families. METHODS: The multi-centre study was conducted from July 2015 to June 2018 at Liaquat University of Medical and Health Sciences, Jamshoro, the University of Sindh, Jamshoro, and Islamia University, Bahawalpur, Pakistan, and comprised families affected with non-syndromic autosomal recessive retinitis pigmentosa. Ophthalmological investigations were done to assess the fundus of the patients and the status of the disease. Pedigrees were drawn and family histories were recorded to find out the mode of inheritance. A 10cc sample of whole blood was obtained from each participant and deoxyribonucleic acid was extracted. Homozygosity mapping was performed using three short tandem repeat polymorphisms closely linked to phosphodiesterase 6A gene, and the linked families were Sanger-sequenced for identification of the mutation. Bioinformatic tools were used to design amplification refractory mutation system assay and to assess the protein structure and pathogenic effects of the mutation. RESULTS: In the 80 consanguineous families, there were 464 individuals, and, of them, 236(51%) were affected with their age ranging between 4 and 80 years. Family history and pedigree drawings revealed autosomal recessive retinitis pigmentosa with early childhood onset. Linkage analysis indicated the homozygosity in 6(7.5%) families. Sanger-sequencing revealed a common mutation c.304C>A (p.Arg102Ser); segregating with the disease in the linked families. CONCLUSION: The findings may offer effective genetic counselling and minimise disease penetration in consanguineous families.

Anti-Infective and Pro-Coagulant Chitosan-Based Hydrogel Tissue Adhesive for Sutureless Wound Closure.

Multifunctional tissue adhesives with excellent adhesion, antibleeding, anti-infection, and wound healing properties are desperately needed in clinical surgery. However, the successful development of multifunctional tissue adhesives that simultaneously possess all these properties remains a challenge. We have prepared a novel chitosan-based hydrogel adhesive by integration of hydrocaffeic acid-modified chitosan (CS-HA) with hydrophobically modified chitosan lactate (hmCS lactate) and characterized its gelation time, mechanical properties, and microstructure. Tissue adhesion properties were evaluated using both pigskin and intestine models. In situ antibleeding efficacy was demonstrated via the rat hemorrhaging liver and full-thickness wound closure models. Good antibacterial activity and anti-infection capability toward S. aureus and P. aeruginosa were confirmed using in vitro contact-killing assays and an infected pigskin model. The result of coculturing with 3T3 fibroblast cells indicated that the hydrogels have no significant cytotoxicity. Most importantly, the biocompatible and biodegradable CS-HA/hmCS lactate hydrogel was able to close the wound in a sutureless way and promote wound healing. Our results demonstrate that this hydrogel has great promise for sutureless closure of surgical incisions.

Point-of-Care Ultrasound in Sternal Notch Confirms Depth of Endotracheal Tube in Children.

OBJECTIVES: To determine if a saline-filled cuff seen at the suprasternal notch on ultrasound corresponds to correct endotracheal tube depth on a chest radiograph (tip at/below clavicle AND ≥ 1 cm above carina). DESIGN: Prospective observational study. SETTING: Tertiary Care Pediatric hospital. PATIENTS: Patients between the ages of 0-18 years requiring nonemergent cardiac catheterizations and endotracheal intubation with a cuffed endotracheal tube were included in the study. Children with anticipated or known difficult airways were excluded. INTERVENTIONS: Ultrasound evaluation of the neck following saline inflation of the endotracheal tube cuff. MEASUREMENTS AND MAIN RESULTS: Ultrasonography of the patient's neck was performed following intubation by a pediatric anesthesiologist. A linear probe was used in transverse axis to identify the saline-filled cuff starting at the suprasternal notch and moving cephalad. A cine-fluoroscopic image, similar to a chest radiograph, was obtained to ascertain the endotracheal tube depth after the cuff was identified sonographically. Endotracheal tube cuffs seen on ultrasound at the suprasternal notch were compared with the endotracheal tube depth on the cine-fluoroscopic image. A total of 75 children were enrolled in the study. The endotracheal tube was seen sonographically at the suprasternal notch in 70 patients of which 60 had complete data (an adequate chest radiograph available for review). Patient ages ranged from 2 months to 18 years with a median age of 4 years. The median endotracheal tube tip to carina distance was 2.4 cm (interquartile range, 1.75-3.3 cm.) The endotracheal tube tip to carina distance was greater than or equal to 1 cm in 57 out of the 60 patients. Endotracheal tube cuff at the suprasternal notch on ultrasound corresponded with correct endotracheal tube depth on chest radiograph with an accuracy of 95% (CI, 86-98%). CONCLUSIONS: Visualization of the cuff at the suprasternal notch by ultrasound demonstrates potential as a means of confirming correct depth of the endotracheal tube following endotracheal intubation.

Calibration-free laser-induced breakdown spectroscopic analysis of copper-rich mineral collected from the Gilgit-Baltistan region of Pakistan.

In this paper, we present the results of compositional analysis of a copper-rich mineral known as malachite, collected from the Gilgit-Baltistan region of Pakistan. A calibration-free laser-induced breakdown spectroscopy (CF-LIBS) technique is employed for determination of elemental composition of the sample. The study aims at the investigation of the presence of precious elements, if any, in minerals of local origin. The laser beam of a 1064 nm wavelength from a nanosecond pulsed $Q$Q-switched Nd:YAG laser was focused on the surface of the sample, and an emission spectrum was obtained with the help of a LIBS2000 spectrometer covering the spectral range between 200 to 700 nm. Results obtained through analyzing the characteristic emission lines of different elements have confirmed the presence of sixteen (16) elements in the investigated sample, viz. Cu, Si, Al, K, Fe, Mn, Ag, Ti, Ba, Sr, Ca, Mg, Na, Li, C, and H. For quantification of the detected elements in the sample, a calibration-free method based on local thermodynamic equilibrium and optically thin plasma model was employed. Plasma parameters, such as electron number density and temperature, were calculated for the purpose of subsequent calculations. Seven elements, viz. Cu, Fe, Si, Ca, Mg, Mn, and Al, were quantified out of 16 initially detected elements, and their concentration in terms of weight percentage was 43.15%, 20.13%, 18.31%, 9.46%, 3.28%, 3.16%, and 2.51%, respectively. The presence of all seven elements quantified by CF-LIBS was confirmed by x-ray fluorescence analysis.

Type 1 Fimbriae and Motility Play a Pivotal Role During Interactions of Salmonella typhimurium with Acanthamoeba castellanii (T4 Genotype).

Amoebic bacterial interactions are the most ancient form of host pathogen interactions. Here, we investigate the fate of Salmonella typhimurium and Acanthamoeba castellanii T4 genotype upon mutual interactions in a nutrition free environment. The role of type 1 fimbriae and motility of S. typhimurium during interactions with A. castellanii has also been investigated. Deletion of genes encoding the type 1 fimbriae subunit FimA, type 1 fimbriae tip protein FimH, chemotaxis regulatory proteins CheA and CheY and major flagella subunits FliC and FljB was performed through homologous recombination. In vitro association, invasion and survival assays of S. typhimurium wild-type and mutant strains were performed upon co-incubation of bacteria with A. castellanii trophozoites in a nutrition free environment. The deletion gene encoding type 1 fimbriae subunit FimA reduced, whereas the deletion of genes encoding flagella subunits FliC and FljB of flagella enhanced the association capability of S. typhimurium with A. castellanii. Invasion of A. castellanii by Salmonella was significantly reduced upon the loss of type 1 fimbriae subunit FimA and type 1 fimbriae tip protein FimH. Co-incubation of S. typhimurium with A. castellanii in phosphate buffered saline medium stimulated the growth of S. typhimurium wild-type and mutant strains. Viable A. castellanii trophozoites count became significantly reduced upon co-incubation with S. typhimurium within 48 h. Type 1 fimbriae play a pivotal role in the adherence of S. typhimurium to the A. castellanii cell surface. Subsequently, this interaction provides S. typhimurium an advantage in growth.

Application of natural crosslinkers on tooth surface: an in-vitro comparative evaluation of resin-dentin bond strength.

OBJECTIVE: To investigate the effect of natural crosslinkers proanthocyanidin, genipin and glutaraldehyde on shear bond strength at the composite resin-dentin interface . METHODS: The in-vitro study was conducted at the Postgraduate Medical Institute, Lahore, Pakistan, from June to September 2018. Exposed dentin surfaces of extracted teeth were conditioned and randomly divided into proanthocyanidin, genipin, glutaraldehyde and control groups according to the type of surface treatment. The dentin surfaces were treated with 6.5% of primers proanthocyanidin, genipin, glutaraldehyde in the relevant groups, while teeth in the control group did not receive any primer application. After thorough rinsing, surfaces of all teeth were restored with a bonding agent and a restorative composite. After 24h, shear bond strength was tested at the Pakistan Council of Scientific and Industrial Research laboratories in Lahore. Pattern of fractures and quality of interface were investigated microscopically at the Lahore campus of COMSATS University, Islamabad. Data was analysed using SPSS 22. RESULTS: Of the 80 teeth, there were 20(25%) in each of the 4 groups. Surface treatment in the three intervention groups significantly raised the shear bond strength at the composite resin-dentin interface compared to the control group (p<0.05). CONCLUSIONS: Chemical modification with collagen crosslinkers improved bond strength at the composite resin-dentin interface.