Dry Ice Research Articles

With the growing concern over increased carbon dioxide concentrations in our planet’s atmosphere, much research is being devoted to improving the methods of carbon capture and storage. Amine-based carbon capture techniques are advantageous due to amine’s ability to react directly and reversibly with carbon dioxide to form solid products. To better understand the composition of the solid products obtained by reactions of carbon dioxide with amines under different conditions, such as reactions with gaseous and solid CO2 (dry ice), spontaneous areal absorbance of CO2, and others, several such reactions were conducted. Single-crystal X-ray diffraction analysis of the seven previously and newly observed carbamate derivatives was carried out. The synthetic and structural results of solid products have been compared with published data on the same materials obtained by different methods. Peculiarities of hydrogen bonding were described for these materials based on the topological approach.

Formation of Unsaturated Carbon Chains through Carbon Chemisorption on Solid CO

Abstract Background and Aims The shortage of kidneys and the growing number of patients requiring a transplant pose a major challenge. Research efforts are focused on developing new therapies to improve both the quantity and quality of transplantable organs. Hypothermic mechanical perfusion (HMP) has enabled the harvesting of organs from marginal donors, such as post-circulatory death donors (DCD). However, these organs are more prone to early post-transplant complications due to their heightened susceptibility to ischemia-reperfusion injury. In a previous study using a DCD model in rats, we demonstrated that the combined use of HMP and the PCSK9 inhibitor (PEP 2-8) could be a promising strategy for renal conditioning prior to transplantation. Specifically, kidneys perfused with PEP 2-8 exhibited a lower rate of ischemic tubular damage, a higher tubular proliferation index, and elevated ATP levels compared to organs perfused with HMP alone. We aim to understand how PCSK9 inhibitors exert their protective effect via metabolomics pathways. Method A total of 15 rats were used as models for Donation after Circulatory Death. The experimental regimen included 30 minutes of warm ischemia followed by 6 hours of cold (4°C) perfusion using either Perf-Gene solution alone for the control group (C) or Perf-Gene solution supplemented with 10 µg of PEP 2-8 for the treatment group (PEP). Each rat's kidney was assigned to either the control or PEP group. Tissue samples from each kidney were embedded in an optimal cutting temperature (OCT) cryogenic well and frozen on dry ice before being stored at –80°C. After extracting the polar metabolites by centrifugation, one-dimensional NMR spectra were acquired using a Bruker Avance NEO 700 MHz spectrometer equipped with a TCI CryoProbe (Bruker BioSpin, Germany). Data acquisition and processing were performed using TOPSPIN 4.1.4 software (Bruker BioSpin, Germany). Automated quantification of metabolites was performed using the ASICS tool. The relative concentrations of the metabolites estimated via ASICS were analyzed using principal component analysis (PCA) after scaling to unit variance. The same data were also subjected to univariate statistical analysis, including the unpaired t-test and the non-parametric Kruskal-Wallis test, to detect significant changes in metabolite concentrations between PEP and C groups. In both cases, the significance level was set at 0.05. In addition, a kidney biopsy was taken and fixed in 10% formalin to perform immunohistochemical analyses. Results ASICS identified and quantified 167 of the 216 library compounds. The relative concentrations obtained were used as input for statistical analysis. PCA analysis did not found evidence of clustering, and the two principal components together accounted for only 45.9% of the total variance of the samples (Fig. 1). Of the 167 metabolites identified, only 5 showed significant differences between the two study groups (Table 1 and Fig. 2). The PEP group exhibited lower levels of oxidative stress metabolites, uremic toxins, and amino acid degradation products (2-oxobutyrate, methylguanidine, dimethylamine, biliverdin, sarcosine), indicating an improved energetic state of the tissue and reduced oxidative damage. These results were confirmed by N-tyrosine immunostaining, a marker of oxidative stress damage, which was reduced in the treated kidneys (median (IQR) CTRL 7.46% (5.67%–9.07%) versus PEP 2.85% (2.42%–3.31%); P < 0.01) (Fig. 3). Conclusion The results of this study highlight the significant potential of PCSK9 inhibitors such as PEP 2-8 in attenuating ischemic injury and enhancing tissue resistance to oxidative stress. The use of PCSK9 inhibitors for ex vivo organ conditioning represents a promising strategy to mitigate the high discard rate of donor kidneys and expand the donor pool. This advancement addresses a critical challenge in transplant medicine, offering new hope for patients awaiting a transplant.

The P-O-P moiety plays a central role in inorganic and biological systems and is considered to be a critical precursor to the phosphate backbone of nucleotides. However, the isolation of the simplest prototype, phosphanyloxyphosphane (H2POPH2), has remained elusive due to its high susceptibility to hydrolysis. Here, we report the first preparation of phosphanyloxyphosphane and its isomer phosphanylphosphinous acid (H2PPHOH) in low-temperature phosphine (PH3)-carbon dioxide (CO2) ices upon exposure to galactic cosmic ray proxies in the form of energetic electrons. These isomers were isolated and identified in the gas phase using tunable vacuum ultraviolet photoionization reflectron time-of-flight mass spectrometry combined with isotopic labeling studies. Our findings not only suggest that the hitherto undetected phosphanyloxyphosphane and phosphanylphosphinous acid can be synthesized in phosphine-rich extraterrestrial ices but also advance our fundamental understanding of the formation of P-O-P and P-P-O linkages via nonequilibrium chemistry under astrophysical conditions.

Capture of greenhouse gases, especially CO2, can reduce the effects of global warming and generate valuable minerals as feedstock for industry. Herein, the mineral products formed by capture of atmospheric CO2 by potassium hydroxide (KOH) in aqueous, aqueous-ethanol, and aqueous-acetone solutions, and aqueous-acetone enriched using solid CO2 are studied. A multimodal analysis combining single-crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), with Pawley and Rietveld refinements, and 850 MHz, 1 GHz, and 1.2 GHz1H, as well as 13C, and 39K nuclear magnetic resonance (NMR), is used to analyze the composition of the mineral products. SCXRD identifies KHCO3 in space group P21/n (transformable to P21/a) as a product from all reactions. PXRD and NMR data show the presence of both crystalline and amorphous phases in products, predominantly as mixtures of KHCO3 and K2CO3 and its hydrates, with KOH as a minor component, except for aqueous-ethanol which gives KHCO3 in high purity. Analysis of complex 1H NMR data is aided by 2D nuclear Overhauser effect spectroscopy (1 GHz), which characterizes COH···OC interactions. Revealing K2CO3 hydration is aided by deconvolution of ultrahigh-field 28.2 T (56 MHz) 39K spectra. This multimodal approach provides new insights into the speciation of potassium minerals from CO2 capture.

Despite growing interest in carbon capture and utilization (CCU), the transformation of captured CO2 into dry ice remains poorly studied, particularly from a systems integration and energy optimization perspective. While previous works have examined individual components such as CO2 absorption, liquefaction, or refrigerant evaluation, no existing study has modeled the full dry ice production chain from capture to solidification within a unified simulation framework. This study presents the first complete simulation and optimization of a dry ice production process, incorporating CO2 absorption, solvent regeneration, dehydration, multistage compression, ammonia-based external liquefaction, and expansion-based solidification using Aspen HYSYS. The process features ammonia as a working refrigerant due to its favorable thermodynamic performance and zero global warming potential. Optimization of heat integration reduced total energy consumption by 66.67%, replacing conventional utilities with water-based heat exchangers. Furthermore, solvent recovery achieved rates of 75.65% for MDEA and 66.4% for piperazine, lowering operational costs and environmental burden. The process produced dry ice with 97.83% purity and 94.85% yield. A comparative analysis of refrigerants confirmed ammonia’s superiority over R-134a and propane. These results provide the first system-level roadmap for producing dry ice from captured CO2 in an energy-efficient, scalable, and environmentally responsible manner.

Anti-lock braking systems (ABSs) play a vital role in vehicle safety by preventing wheel lockup and maintaining stability during braking. However, their performance is strongly affected by variations in tire–road friction, which often limits the effectiveness of conventional controllers. This research proposes and evaluates a fuzzy logic controller (FLC)-based ABS using a quarter-vehicle model and the Burckhardt tire–road interaction, implemented in MATLAB/Simulink. Two input variables (slip error and slip rate) and one output variable (brake pressure adjustment) were defined, with triangular and trapezoidal membership functions and 15 linguistic rules forming the control strategy. Simulation results under diverse road conditions—including dry asphalt, concrete, wet asphalt, snow, and ice—demonstrate substantial performance gains. On high- and medium-friction surfaces, stopping distance and stopping time were reduced by more than 30–40%, while improvements of up to 25% were observed on wet surfaces. Even on snow and ice, the system maintained consistent, albeit modest, benefits. Importantly, the proposed FLC–ABS was benchmarked against two recent studies: one reporting that an FLC reduced stopping distance to 258 m in 15 s compared with 272 m in 15.6 s using PID, and another where PID outperformed an FLC, achieving 130.21 m in 9.67 s against 280.03 m in 16.76 s. In contrast, our system achieved a stopping distance of only 24.41 m in 7.87 s, representing over a 90% improvement relative to both studies. These results confirm that the proposed FLC–ABS not only demonstrates clear numerical superiority but also underscores the importance of rigorous modeling and systematic controller design, offering a robust and effective solution for improving braking efficiency and vehicle safety across diverse road conditions.

Abstract Microbiomes refer to the full spectrum of microorganisms within a specific environment and shifts in microbial abundance can influence disease development. Since many bacteria are unculturable in laboratory settings, techniques such as 16S rRNA gene sequencing are essential for profiling microbial communities in complex biological samples. Liver abscesses in cattle, defined by localized bacterial infections in the liver parenchyma, are typically caused by the translocation of gastrointestinal bacteria and can result in reduced animal performance and carcass yield. This study aimed to characterize the microbial communities present in liver abscesses from beef carcasses processed in the Texas Panhandle region using 16S rRNA sequencing. A total of 697 beef carcasses were screened for liver abscesses through random sampling. From these, 15 liver samples (9 abscessed, 6 non-abscessed) were collected and immediately frozen on dry ice. DNA was extracted using the GeneJET Genomic DNA Purification Kit, with quality assessed by agarose gel electrophoresis and quantified using a NanoDrop 2000 Spectrophotometer. The V4 region of the 16S rRNA gene was amplified using primers 515F (5’ GTGYCAGCMGCCGCGGTAA 3’) and 806R (5’ GGACTACNVGGGTWTCTAAT 3’). Library preparation and sequencing were performed using the MR DNA analysis pipeline. Sequences were filtered for quality, dereplicated, denoised, and screened for chimeras. High-confidence sequences were taxonomically classified using BLASTn against a curated NCBI-derived reference database (www.ncbi.nlm.nih.gov). Of the 697 carcasses screened across Texas, New Mexico, Kansas, Colorado, and Oklahoma, 44 tested positive for liver abscesses (6.3%). Positive cases were observed in 32 out of 431 cattle from Texas, 6 of 128 from New Mexico, 2 of 31 from Kansas, and 4 of 94 from Oklahoma. No positive cases were identified from Colorado. Prevalence by sex showed 6 positives among 97 males and 38 among 600 females. Among cattle younger than 30 months, 25 tested positive, while 19 over 30 months were affected. On average, positive liver samples exhibited at least three abscesses. 16S rRNA analysis revealed Fusobacteria and Porphyromonas as the dominant taxa in abscessed liver tissues. Although both healthy and abscessed livers contained microbial populations, these two genera were consistently abundant in abscessed samples. The 6.3% prevalence rate falls within expected global ranges but is lower than initially anticipated. Results suggest that the occurrence of liver abscesses is not significantly influenced by cattle origin, age, or sex. These findings contribute to a broader understanding of microbial dynamics in bovine liver abscesses and support the utility of 16S rRNA sequencing in animal health research.

Abstract Ruminal papillae histology and ruminal volatile fatty acid (VFA) profile of feedlot heifers with abscessed and non-abscessed livers were evaluated. A randomized complete block (kill group) design was used to source heifers (beef-on-dairy) finished in a steam-flake corn-based diet, upon harvest, in which 94 and 110 ruminal tissue and fluid collections were performed from animals with and without liver abscesses, respectively. Selection of animals were determined in pairs, as abscesses were identified at the viscera inspection line. A 1-cm2 individual fragments from the ventral cranial-sac of the rumen were collected for the histological assessment, while ruminal fluid was taken and immediately frozen (dry ice). The histological laminas were prepared (embedded in paraffin wax, sectioned at 4 µm and stained with hematoxylin and eosin) for microscopic cellular assessment. Ruminal fluid was processed and analyzed for VFA using gas chromatography. The GLIMMIX procedure of SAS was used for statistical analysis utilizing animal as the experimental unit, the fixed effect of liver abscess presence, size (small or large) intensity (local or diffuse), location (left, right, both), or diffusion (local or diffuse), while lot within harvest-group was used as random effect. The papillae histology identified (P ≤ 0.02) that animals with liver abscess had papillae with greater height, area, and thinner keratin layer while there was no difference between width (P = 0.88). Animals with liver score (A+) showed a thinner papillae keratin layer (P = 0.05), while those with large abscesses show greater heigh (P = 0.04) and thinner keratin layer (P = 0.04). Animals with diffused abscesses across the liver had papillae that were taller (P = 0.06), with greater area (P = 0.05), and thinner keratin layer (P = 0.04) compared to those with non-abscessed liver. Abscess lobe location (P ≥ 0.11) and papillae cellular mitotic index were not affected (P ≥ 0.64) by any variable in current assessment. Ruminal VFA profile, total, and C2:C3 molar proportions (collected upon harvest time) were not affected by the presence of liver abscess (P ≥ 0.19). Ruminal papillae histologic microscopic measurements revealed that animals with liver abscess (influenced by presence, size, and diffusion) had more pronounced and vulnerable ruminal papillae tissue.

The acceptability of the approximation of the equilibrium state of plasma if it is used in gasification processes is discussed. The development of technologies for converting solid biomass as an available raw material for distributed electricity generation in Ukraine is carried out to obtain both energy and chemical products. The use of biomass gasification technologies and direct conversion of fuel gas energy into electricity in solid oxide fuel cells allows achieving electrical efficiency of power plants of 42 % or more. Plasma torches are used to produce hydrogen-rich gas with low content of high-molecular compounds, as well as to achieve operating gas temperatures before cells mentioned. The conversion of wood coal, wood waste, and walnut shells was studied at the plasma steam-air gasification unit. The use of a steam plasma torch for steam reforming of volatiles in the pyrolysis zone of an air-gas generator leads to the H2/CO molar ratio and H2 yield increase, as well as to the equivalence ratio and N2 concentration decrease in all cases of the selected biomass types. It was found that the yield of pure hydrogen could be increased by adding water shift reactors and membrane hydrogen separation to the existing plant. The production of pure H2 is 0.6 Nm3/h, the cold gas efficiency of H2 production is 47.7 %, and the electricity consumption is 27.75 kWh/kg of H2. Due to plasma steam-air gasification of solid biomass and CO conversion, the electricity consumption for H2 production will be 50.8 % less than the electricity consumption for water electrolysis. It is shown that compared to the latter case, the cost of H2 production by converting solid biomass, taking into account the costs of electricity, biomass, and water in Ukraine, is 39–44 % lower than the cost of hydrogen obtained by water electrolysis. Bibl. 52, Fig. 1, Tab. 9.

Abstract Background Numerous clinical analytes are sensitive to thermal degradation and require specimens to be transported in a frozen state to maintain stability. Cold chain transport for frozen specimens typically uses dry ice. While effective, dry ice is not suitable for use in most collection sites due to the cost of constant replenishment and the required hazardous good training for site staff. Furthermore, dry ice is bulky, embodies significant CO2 emissions, and is subject to a 5.5lb commercial air-shipping limit which restricts endurance time. Here we introduce a set of sub-zero phase change materials (PCMs) based on low-cost salt-in-water formulations. These inexpensive PCMs were packaged in commercial heat-seal jugs and bottles to facilitate rapid prototyping and deployment. Methods Three low-cost, non-toxic PCM formulations were developed from a mixture of tap water and the following commodity salts near the eutectic concentration: (1) KCl (2) a mixture of KCl and NaCl, (3) a mixture of KCl, NH4Cl, and NaCl. The melting temperatures were measured by exposing test packages to an environmental chamber while logging internal temperature. Two packing configurations were developed for frozen specimens using these PCMs: (1) a large EPS insulated shipper to provide multi-day subzero shipping (2) vacuum insulated containers for rapid freezing and short-term lockbox maintenance To evaluate the first configuration, 4x 32oz jugs containing a solution of KCl in water were pre-frozen in a conventional -20C freezer and placed in a standard EPS shipper. An identical EPS shipper was filled with the commercial air shipment limit (5.5lb/2.5kg) dry ice as a control, and both shippers were exposed to simulated summer conditions for 72hrs with internal temperature logging. To evaluate the second test configuration, 6oz bottles containing each of the 3 saltwater PCMs were pre-frozen and placed in 18oz vacuum flasks along with a 4mL specimen tube containing water. The internal temperature of each specimen tube was measured by a temperature logger over the course of 36hrs under varying external temperature. The initial freezing rate was compared to a matched 4mL specimen tube placed in a conventional -20C freezer. Results The following phase change temperatures were assessed for the 3 salt-in water PCMs: -10.8C (KCl), -23.4C (NaCl + KCl), -25.8C (NaCl+KCl+NH4Cl). In the first package test set, the KCl-based PCM outperformed dry ice, maintaining sub-zero temperature within the EPS shipper for 48hrs compared to 40hrs for the dry ice control. In the second package test, specimens placed in a vacuum flask with frozen KCl/NaCl and KCl/NaCl/NH4Cl PCMs froze and reached -10C in 28 minutes and 32 minutes respectively compared to 86 minutes for conventional freezing. Both PCMs maintained specimen temperature below the freezer temperature (-20C) for more than 32hrs. In a 6 month pilot test of a KCl-based vacuum flask system in lockboxes across 5 sites in Florida, no instances of thawed specimens were observed during pickup. Conclusion Salt-in-water based PCMs stored in plastic bottles or jugs are a cost-effective and reusable alternative to dry ice for fast freezing, short-term maintenance, or multi-day shipping of frozen specimens.

Abstract Background The PreTRM® Test is the only commercially available blood-based biomarker test that provides an early, accurate and individualized risk prediction for spontaneous preterm birth in asymptomatic singleton pregnancies. The PreTRM test uses LC-MS/MS technologies to produce response ratios for peptides derived from two biomarker proteins, IGFBP4 and SHBG, which are used in a multi-analyte algorithmic assay to produce a PreTRM risk result. A major challenge in early commercialization was transporting frozen serum specimens with dry ice. This method is costly, hard to manage, and temperature can only be maintained for a short time, especially in the summer. Thus, studies were initiated to test alternative shipping methodologies, including refrigerated shipping using standard Styrofoam shippers with ice packs, refrigerated shipping using Therapak Nanocool™ evaporative cooling shippers and ambient-temperature shipping with dried collection and shipping using MITRA® volumetric absorptive microsampling (VAMS®) technology. Methods Three temperature stability studies were completed using a two-arm study approach, comprising a test arm with samples subjected to a 48-hour variable temperature stress cycle and a control arm of samples held at -80°C before testing. The three studies included: (1) Styrofoam shipping containers with 3 ice packs; (2) NanoCool evaporative cooling shippers; and (3) Mitra VAMS tips in foil pouches containing desiccant cards. The temperature stress cycles were: 4 hours at 23°C; 2 hours at 45°C; 36 hours at 30°C; and 6 hours at 45°C before laboratory testing. All samples were analyzed using Agilent 6495 LC-MS/MS instruments. The Styrofoam and NanoCool studies included 72 serum samples from individual donors each, frozen at -20° C prior to temperature stress. Evaluation of VAMS tips included 84 serum samples, from individual donors, that were dipped and dried before temperature stress. Agreement was assessed by Deming regression and Pearson correlations in R. Results Samples from the shippers with ice packs subjected to temperature stress cycles showed a Deming regression slope of 1.01 and a Y-intercept of 0.04 and a Pearson’s r of 0.920. Results from NanoCool shippers subjected to temperature stress cycles showed a Deming regression slope of 0.92 and a Y intercept of -0.12 and a Pearson’s r of 0.939. Data obtained using Mitra tips yielded a Deming regression slope of 1.0, a Y-intercept of 0.28 and a Pearson’s r of 0.964. Conclusion Samples sent on ice packs showed lower results for analytes than did the other studies, but our algorithm corrected for the low response. It was determined not to pursue this shipping method due to the loss of signal. Both NanoCool shippers and ambient-temperature serum collection and shipping using VAMS technology were found acceptable for use. However, due to higher cost and 48-hour shipping time window of refrigerated samples in the NanoCool shippers, compared to the longer dried stability, large scale production with short lead times, and lower cost of the Mitra device, ambient-temperature serum collection on VAMS devices is the most promising method of sample submission for the PreTRM Test.

Hard carbon (HC) has emerged as a promising anode material for sodium-ion batteries (SIBs) owing to its superior sodium storage performance. However, the high cost of conventional HC precursors remains a critical challenge. To address this, coal─a low-cost, carbon-rich precursor─has been explored for HC synthesis. Nevertheless, the dense structure of coal tends to form highly graphitized microcrystalline domains during high-temperature carbonization, leading to a suboptimal reversible specific capacity and initial Coulombic efficiency (ICE). In this study, we propose a low-temperature assisted ball milling (LT-ABM) strategy to modify carbonized bituminous coal, employing dry ice (solid CO2) as the grinding medium. This approach leverages a physicochemical synergistic effect to enhance defect concentration while mitigating particle agglomeration. The LT-ABM process facilitates surface etching of HC materials, suppresses cold agglomeration induced by van der Waals forces, and yields uniform nanoparticles with an elevated oxygen content. The synthesized hard carbon material demonstrates a reversible specific capacity of 308.14 mAh g-1 under a current density of 30 mA g-1, while maintaining 78% of its initial capacity after 500 cycles at an elevated current density of 300 mA g-1. Kinetic analyses reveal that the slope capacity correlates strongly with surface defect concentration, aligning with the ″adsorption-insertion-filling″ sodium storage model. Our findings demonstrate that controlled defect engineering can significantly improve the reversible capacity of coal-derived HC. However, the limited plateau capacity restricts high-rate performance, suggesting a trade-off between defect density and Na+ diffusion kinetics. This work provides a viable pathway for the rational design of cost-effective, high-performance coal-based HC anodes.

Accuratesimulation of vibrational spectra in the solid state remainsa major challenge due to the combined effects of anharmonicity, intermolecularinteractions, and resonance phenomena. In this work, we introducea generalized second-order vibrational perturbation theory (GVPT2)framework for the quantitative computational spectroscopy of molecularsolids. The method balances efficiency and accuracy through a perturb-then-diagonalizeapproach in which resonant terms are excluded in the initial perturbativetreatment and subsequently handled more accurately through a variationalapproach. This strategy ensures numerical stability while capturingessential vibrational couplings. As a representative application,we investigated the infrared spectrum of solid carbon dioxide (dryice), a prototypical system exhibiting strong anharmonic effects andFermi resonances. The generalized VPT2 approach accurately reproducesboth absolute band positions and splitting patterns, yielding resultsin excellent agreement with the experimental data. These findingsdemonstrate the potential of the method for reliable and transferableanharmonic vibrational analysis across a broad class of solid-statesystems.

Purpose In cold weather conditions, the thermal performance of multi-layered fabrics plays a critical role in maintaining comfort and safety. This study introduces a unique testing apparatus that has been designed and developed to evaluate the thermal characteristics of multi-layer fabrics specifically designed for extreme cold weather conditions. Design/methodology/approach The thermal conductivity measurement instrument employs a dual-plate methodology, incorporating precise procedures to replicate extreme cold conditions (down to −45°C) in the top zone using dry ice, while also establishing a regulated hot zone (bottom zone) that mimics human skin temperature (33°C) through the use of an electric heater and a proportional-integral-derivative (PID) temperature controller. Findings The experimental apparatus revealed consistent temperature fluctuations (±<0.5°C) and good thermal stability in the bottom zone during both short and long-duration testing periods. In the cold zone, the instrument effectively maintained lower temperature fluctuations (±<2°C) during shorter testing periods. However, because of rapid dry ice sublimation, extended testing durations showed larger temperature fluctuations (±˜5°C). Research limitations/implications These findings also demonstrate the limitations of dry ice as a cooling medium for extended periods of testing time. Practical implications This study aims to enhance the functioning of multi-layer fabrics, which are in demand for cold-weather clothing, based on the tested equipment. Originality/value Though several commercial testing devices and research models based on steady-state and non-steady-state (transient) approaches have been developed, there is still a significant gap in accurately simulating cold weather conditions when evaluating cold weather clothing, with the exception of the thermal manikin method.

The impact of dry ice exposure on pH change during biologics transport and mitigation strategies.

Background: Breast cancer is the commonest malignancy among women globally. Triple negative breast cancer (TNBC) accounts for 10-20% of invasive breast cancer out of the worldwide breast cancer burden. Histopathology is the gold standard investigation but it has no prognostic value, and genetic analysis is not possible by this test. Tumors release biomarkers like circulating tumor DNA (ctDNA), mRNA and glycoprotein during apoptosis. Different cancers release different circulating tumor DNA (ctDNA), and different subtypes of tumors arising from the same tissue have different ctDNA, and it can be detected in patients’ plasma for diagnosis, prognosis, evaluation of treatment, as well as genetic analysis of the tumor. Objective: To detect circulating tumor DNA (ctDNA) in triple-negative breast cancer (TNBC) patients in Bangladeshi women. Method: This cross-sectional descriptive study was conducted in the Department of Biochemistry, Dhaka Medical College, Dhaka, during the period of January 2022 to December 2022. Sixteen (16) diagnosed Triple Negative breast cancer (TNBC) patients were selected from Dhaka Medical College Hospital (DMCH) and Bangabandhu Sheikh Mujib Medical University (BSMMU) by purposive sampling. Data was collected using a detailed pre-formed questionnaire. 8.4 ml venous blood was collected in Norgens cf- DNA/cf-RNA preservative tubes. Plasma separation was done, which was stored in - 80° C temperature freezer and was sent to the University of Chicago on dry ice where ctDNA was extracted. Results: Age range of this study was 30-60 years. Mean BMI was 23.44 ±2.98 Kg/m2. Almost all the cases (93.75%) gave history of regular menstrual cycle. 5 patients had menopause. Mean age of menarche and menopause was 12.81 ±0.75 and 47.6 ±2.97 years, respectively. Oral contraceptive pill was most (62.5%) preferable method. Among 15 married women in this study, all were childbearing and had history of lactation except one case. Mean age of first child birth was 20 ±2.39 years. Only one patient (6.25%) aged 53 years had a positive family history. None of the patients had stage IV nor grade IV disease. ctDNA was detected in plasma samples of all patients, and results of genetic analysis was shown in terms of Single Nucleotide Variations (SNVs), Insertion and/or Deletion (Indels). Conclusion: ctDNA can be detected inTNBC patients of Bangladeshi women.

Artificial ground freezing by solid carbon dioxide—Analysis of controlling factors on ice-wall formation

Simulation and experiment of dry ice jet freezing on seedless lychee

Quantitation of plasma and urine 3-methoxytyramine using ID‑LC-MS/MS: A candidate reference measurement procedure and its application to evaluate the results from more than 100 routine LC-MS/MS labs in China.