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Cryopreservation, or the storage at liquid nitrogen temperatures (-196°C), of embryogenic cells or somatic embryos allows their long-term conservation without loss of their embryogenic capacity. During the last decade, protocols for cryopreservation of embryogenic material of woody species have been increasing in number and importance. However, despite the large experimental evidence proved in thousands of embryogenic lines, the application for the large-scale conservation of embryogenic material in cryobanks is still limited. Cryopreservation facilitates the management of embryogenic lines, reducing costs and time spent on their maintenance, thus limiting the risk of the appearance of somaclonal variation or contamination. Somatic embryogenesis in combination with cryopreservation is especially useful to preserve the juvenility of lines while the corresponding clones are being field-tested. Hence, when tree performance has been evaluated, selected varieties can be propagated from the cryostock. The traditional method of slow cooling or techniques based on vitrification are mostly applied procedures. For example, slow cooling methods are widely applied to conserve embryogenic lines of conifers. Desiccation based procedures, although simpler, have been applied in a smaller number of species. Genetic stability of the cryopreserved material is supported by multiloci PCR-derived markers in most of the assayed species, whereas DNA methylation status assays showed that cryopreservation might induce some changes that were also observed after prolonged subculture of the embryogenic lines. This article reviews the cryopreservation of embryogenic cultures in conifers, fruit species, deciduous forest species and palms, including a description of the different cryopreservation procedures and the analysis of their genetic stability after storage in liquid nitrogen.

The lignocellulosic biomass recalcitrance is the uppermost factor for the utilization of this renewable resource. The development of new pre-treatments, addressed to enhance performance in lignocellulosic biomass conversion into biofuels, fine chemicals, and as potential sources of building blocks for materials, must be focus in two main areas: effectiveness (cost-effective and chemical effective) and green chemistry. In this research, a set of different biomass sources (farmer, harvested wild trees and secondary products) were studied to evaluate the high efficiency of the non-liquid nitrogen (LN) and LN-treated biomass samples’ planetary ball milling performance. The samples have been characterized by particle size distribution, thermogravimetric, FT-IR, statistical chemometric and chemical oxidation analysis. The results have shown a high level on the rupture of the crystallinity and depolymerization degrees of the cellulose and the lignin, for both, non-LN and LN-treated samples. The thermogravimetric analysis showed a clear diminishing in temperature degradation, and a larger amount of biomass degraded at lower temperature, as well as, a high chemical oxidation degree than not milled samples. Finally, the LN-treated samples even exhibited a lower degradation temperature, a larger amount of biomass degraded at lower temperature and a higher oxidation degree, than those non-LN milled.

Bone grafting has emerged as a key solution in bone defect management such as allograft, graft of bone from another individual. However, bone allografts usually undergo rigorous preparation to eliminate immune-triggering elements. The deep-freezing methods may delay graft use, while cryopreservation using liquid nitrogen allows rapid freezing but may alter graft characteristics. The aim of this study was to investigate the post-preservation changes in bone allograft characteristics and to compare the effectiveness of deep-freezing and liquid nitrogen methods using animal model. An experimental study using a post-test only control group design was conducted. Fresh-frozen femoral cortical bone was obtained from male New Zealand white rabbits. Preservation by deep-freezing involved placing bone samples in a -80°C freezer for 30 days. For liquid nitrogen preservation, bone grafts were immersed in liquid nitrogen for 20 min, followed by a 15-min rest at room temperature and a final immersion in 0.9% sodium chloride at 30°C for 15 min. Bone samples then underwent evaluation of cell viability, compression, and bending tests. Cell viability test employed the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and the compression and bending tests used the Universal Testing Machine (UTM). Independent Student t-test or Mann-Whitney U test were used to compare the methods as appropriate. Our study found that the use of deep-freezing and liquid nitrogen resulted in similar outcomes for cell viability, compression, and bending tests, with p-values of 0.302, 0.745, and 0.512, respectively. Further exploration with larger sample sizes may help to optimize the methods for specific applications.

source:Research communications. 1993, 16, 130-137, source:http://www.ifo.or.jp/rc_pdf/16.pdf

source:Research communications. 1991, 15, 105-118, source:http://www.ifo.or.jp/rc_pdf/15.pdf

This seminar will be a scientific exploration of the food we eat and enjoy. Each week we shall have a scientific edible experiment that will explore a specific food topic. This will be a hands-on seminar with mandatory attendance of at least 85%. Topics include, but are not limited to, what makes a good experiment, cheese making, joys of tofu, food biochemistry, the science of spice, what is taste? This course is the second in a series of two courses in kitchen chemistry. The prerequisite to Advanced Kitchen Chemistry is ES.287 Kitchen Chemistry, which is also on OCW.

In this study, we investigated the effect of overrun, fat destabilization degree and ice crystal size on viscoelastic behavior, hardness and melting properties of ice cream by changing only one parameter at a time. To vary the degree of fat destabilization, we changed the emulsifier type; to modify overrun and ice crystal size, we used either a batch freezer or liquid nitrogen freezing upon whipping. Fat destabilization degree, overrun and ice crystal size were measured to determine the structural differences between the studied samples. Furthermore, viscoelastic behavior upon increasing strain and temperature were evaluated by oscillatory rheology. Hardness and meltdown tests were performed to explore the role of different microstructural elements. Depending on the composition of the ice cream, we identified two main types of structures: one dominated by the ice crystals, and one dominated by a fat network. The results showed that the ice crystal-dominated structure contributed more than the fat network to viscoelastic behavior and hardness, whereas the fat network had a larger effect on the melting process. Only a limited effect of ice crystal size on the properties of the ice cream was seen, independently of the kind of dominated structure. In both types of ice cream, overrun had a large effect on mechanical properties, but only in ice crystal-dominated samples it also affected melting. This research provides a better understanding of the role of multiple structural elements in ice cream, which can be used for its reformulation.

To promote the commercial use of high-temperature superconducting devices, the ability to detect temperature anomalies easily and reliably and thereby protect the devices is important. In particular, a sudden local temperature increase due to a superconducting-to-normal transition can damage a device. In the present study, we propose a method to detect explosive boiling of superheated liquid nitrogen sealed in a long thin tube using a pressure gauge connected to the end of the tube. Experiments using a stainless-steel tube with an inner diameter of 1 mm and a maximum length of 50 m under various conditions showed that the local temperature rise caused explosive boiling at a temperature slightly below the superheat limit of 110 K for liquid nitrogen; the results also showed that the rapid pressure increase was transmitted to the end of the tube at approximately the speed of sound (∼830 m/s). The proposed method of placing a thin tube along high-temperature superconducting conductors or cryogenic structures can be used to easily detect a local temperature rise., source:Kazuya Takahata, Explosive boiling of liquid nitrogen in a long thin tube and its application to the detection of a local temperature rise, Cryogenics, Volume 122, 2022, 103419, ISSN 0011-2275, https://doi.org/10.1016/j.cryogenics.2022.103419., source:https://doi.org/10.1016/j.cryogenics.2022.103419

The cryogenic coolant is important as an electrical insulation in an immersion cooling. One of the dielectric breakdown mechanisms of the cryogenic coolant is via bubbles, caused by partial discharge (PD). The insulation performance has been discussed with PD parameters and breakdown voltage. However, the essential PD mechanism has not been clarified in detail. In this paper, PDs in gaseous and liquid nitrogen were discriminated based on characteristics of the original PD waveform. It was shown that the difference in charge behavior appears significantly in the fall time of the original PD waveform., source:https://doi.org/10.1585/pfr.15.2401025

The critical heat flux in liquid hydrogen is ten times higher than that in liquid helium and is approximately half of that in liquid nitrogen. Since the resistivity of pure metal such as copper or silver at 20 K is less than one-hundredth of that at 300 K, HTS magnets immersed in liquid hydrogen are expected to satisfy the fully cyostable condition or to be stable against high resistive heat generation enough for quench detection at a practical current density. In order to examine cryostability of HTS magnets in liquid hydrogen, a pool-cooled Bi2223 magnet with a 5 T magnetic field at 20 K has been designed, fabricated and tested in liquid nitrogen prior to excitation tests in liquid hydrogen. The magnet consists of six outer double pancake coils with the inner diameter of 0.20 m and four inner double pancake coils with the outer diameter of 0.16 m. The resistive voltage to initiate thermal runaway in the coil assembly in liquid nitrogen was higher than 1 V that is sufficient high for quench detection., source:S. Imagawa et al., "Design, Fabrication and Soundness Test of A Bi2223 Magnet Designed for Cooling by Liquid Hydrogen," in IEEE Transactions on Applied Superconductivity, vol. 32, no. 6, pp. 1-5, Sept. 2022, Art no. 4604605, doi: 10.1109/TASC.2022.3172271., source:http://doi.org/10.1109/TASC.2022.3172271, identifier:0000-0003-1454-8117

Microbubbles, along with ultrasound waves (frequency greater than 20 kHz), play an essential role in biomedical and engineering applications, e.g. the medical imaging of internal organs, permeabilization of tissues, food/dairy processing, and nanoparticle generation. For example, tissue-permeabilization is made possible when oscillating bubbles in the presence of sound waves produce recirculation flows in the surrounding fluid (commonly known as microstreaming). Alongside, bubble-collapse generates high temperature and pressure that can help break down molecules into free radicals, triggering chemical reactions. But, there is a dearth of information and understanding of the relationship between these physical and chemical effects with applied power and frequency of the ultrasound, when the amount of dissolved gas is less and surplus gas intrusion from outside is checked. This study addresses some of these issues through different experimental and numerical techniques. An experimental sonoreactor setup is fabricated to connect to a degassing setup and different frequency plates, thereby allowing the measurement of radical generation during bubble oscillation. Sonochemiluminescence and iodide dosimetry tests are conducted in the water in this setup without overheating or gas-intrusion. Again, the same liquid is transferred without any agitation to another in-house fabricated glass cell connected to a frequency transducer. This arrangement facilitates the levitation of a single bubble registering stable oscillation, thereby generating flow structures in the adjacent liquid. These are captured using particle image velocimetry (PIV) for different cases of applied power. In addition, computational fluid dynamics is performed to closely resolve these flow features and explore these phenomena over a broader applied power and frequency parameter space. It has been observed from our chemical investigations in water that at low dissolved gas conditions, limited radical generat

Neltuma alba Gris is an emblematic specie of Chaco Ecoregion for its wood and fruits value. This research show that algarrobo blanco´s seeds can cryopreserve without affecting germination power and energy. The seeds were kept for three months at 24°-30°C, (-18°C) and (-196°C). Later, they were mechanically scarified and sown in black soil and sawdust (3: 1). The results were subjected to non-parametric Kruskal-Wallis tests, analyzing germination power, energy and vigor. The test did not detect significant differences between treatments. The nodal segments (2 cm long) obtained from plants of seeds were used for in vitro regeneration in MS culture medium supple-mented with 3 mg L-1 IBA and 0.05 mg L-1 CIN, The rooting percentages obtained were high (87-90%). There are no significant dif-ferences between treatments tested. The storage of seeds at 24°-30°C is the most approppiate to rich high percentages of germination, Neltuma alba Griseb es una especie emblemática de la Ecorregión Chaqueña, por el valor de su madera y frutos. Los resultados de la presente investigación, dan cuenta de que las semillas de algarrobo blanco pueden ser críoconservadas sin afectar el poder y la energía para germinar. Las semillas fueron conservadas por tres meses a Temperatura ambiente (24° y 30°C, Congelamiento (-18°C) y Nitrógeno líquido (-196°C). Posteriormente, fueron escarificadas mecánicamente y sembradas en tierra negra y aserrín (3:1). Los resultados fueron sometidos a pruebas no paramétricas de Kruskal-Wallis, analizándose poder, energía y vigor germinativo, y no se detectaron dife-rencias significativas entre tratamientos. Para la regeneración in vitro en medio de cultivo MS suplementados con 3 mg L-1 IBA y 0,05 mg L-1 CIN, se utilizaron segmentos nodales de 2 cm de longitud obtenidos de plántulas provenientes de semillas. Los porcentajes de enraizamiento obtenidos fueron elevados (87-90%). No existiendo diferencias significativas entre los tratamientos ensayados. El almacenamiento de semillas a 24°-30°C resulta ser el más apropiado para alcanzar altos porcentajes de germinación

In cryogenic fracturing, a rock surface exposed to cryogenic fluids undergoes a large thermal gradient, and the resultant local tensile stress overcomes rock strength and initiates fractures. This study investigates the development of cracks generated from the cryogenic treatment of a borehole under no external confining stress on specimens. The experiments were performed on transparent PMMA specimens to observe fracture proliferation around boreholes. Liquid nitrogen was flowed through the boreholes to cool the borehole surface. The results show that initial fracture growth is characterized by abrupt starts and stops, and as the fracture propagates outward, the growth appears more continuous. In an early stage, horizontal/radial fractures and vertical fractures are the defining patterns. Horizontal fractures tend to be separated by a specific exclusion distance (i.e., spacing between cracks). While distinct horizontal/vertical fractures and exclusion distance manifest themselves at an early stage, fractures resulting from fracture interactions and curvatures can develop into complex shapes at later stages. Cryogenic thermal loading induces distinctively curved fractures. The tendency of curvature may prevent greater penetration. An increase in the borehole pressure during liquid nitrogen flow, however, can lessen fracture tortu-osity and facilitate radial propagation. A high flow pressure and rate are also advantageous in that they accelerate cooling and fracture propagation.

For extra-high-voltage high-temperature superconducting (HTS) cables, not only high electrical insulation performance but also low dielectric loss is required. Therefore, we focus on a porous synthetic paper with lower dielectric loss, e.g., Tyvek polyethylene nonwoven fabric, than that of polypropylene laminated paper (PPLP), which has been used for a conventional HTS cable insulation system. In this paper, we compare partial discharge inception characteristics for different liquid nitrogen/synthetic paper composite insulation systems. The partial discharge inception electric field strength in the composite insulation system depends on the electric field strength in the porous area of synthetic paper.

The cryopreservation of dormant buds can be a feasible method for preserving germplasm of cold-tolerant woody plants. In the present study, we evaluated the effects of pre-desiccation, thawing method, and the rehydration of bud sections on the post-cryopreservation recovery of dormant blackcurrant buds in vitro. The estimated recovery of small- and medium-sized buds was 80.1 and 62.7% respectively for desiccated buds and 67.8 and 72.3% respectively for non-desiccated buds. The pre-desiccation of bud sections enhanced the number of the shoots regenerated from vegetative buds (2.3 vs. 4.7). The estimated recovery of fast-thawed buds was better after 14-day than after 7-day rehydration (85 vs. 59%). In slowly thawed buds the difference between 14-day and 7-day rehydration was not significant (73 vs. 62%). The estimated recovery of vegetative and flower buds was 77.7 and 41.1% respectively after 7-day rehydration, and 95.2 and 43.6% respectively after a 14-day rehydration period. The rehydration of bud sections was not necessary for the in vitro recovery of non-desiccated, fast-thawed buds. Of the 23 blackcurrant cultivars cryopreserved using non-desiccated dormant buds collected from a greenhouse, the estimated recovery of 22 cultivars ranged between 42 and 90%.

In this work we present the design and thermal modeling of a cold finger open cycle cryostat that operates with liquid nitrogen, intended to be implemented into the Mössbauer spectrometer available at the Universidad EAFIT of Medellín, Colombia, with the purpose of obtaining a low cost and good performance system for the acquisition of low temperature Mössbauer spectra. Initially, we propose a design that meets the requirements of the spectrometer, afterward, based on the initial design, we develop the calculations of heat flow into the system. The results of the thermal model allowed us to define the dimensions of the vessels, as well as calculate the evaporation time of a given column of liquid nitrogen in the cryogenic vessel. Finally, some progresses in the construction of the physical prototype are presented. © 2019, Springer Nature Switzerland AG.

In this work, we present a heat flow analysis for a conceptual design of an open cycle liquid nitrogen cryostat with application in Mössbauer spectroscopy. Initially, we made a study of the different configurations of Dewar type cryostats reported in the literature. These configurations are based on existing designs and the Mössbauer spectrometer requirements of the Instrumentation and Spectroscopy Laboratory at Universidad EAFIT in Medellin. From this study, we establish our own conceptual design. A first heat flow analysis in stationary state was calculated to obtain the dimensions of the reservoir vessel. The heat flow model obtained predicted an adequate evaporation time of the liquid nitrogen for the acquisition of Mössbauer spectra. For this model we employed the Fourier's law, the heat flow by radiation in grey bodies and the properties of 304 stainless steel, 6061 aluminium alloy and OFHC copper. In consequence, the mechanical design of the cryostat was defined and the new heat loads associated with it were added to the initial model. Finally, the prototype was built, the model was tested and some final corrections were made. © Published under licence by IOP Publishing Ltd.

Introduction: The hard seed is the main cause of dormancy in most of the Leguminoseae species. Seed scarification methods, where physical damage is sought to break hard seed coat without diminishing quality, have been modified over time to make them more effective. The most commonly used seed scarification methods include heat, mechanical scarification, and freeze-thaw. Some methods for freeze-thaw scarification include ultra-low temperature immersion in liquid nitrogen (LN, -196 ° C). Objective: Determine the effectiveness use of Liquid nitrogen (LN) as a scarification method to overcome dormancy in seeds of species of the Leguminoseae family. Methodology: The physiological quality of all freshly harvested seeds was determined and scarified by direct immersion in LN for 30 minutes. Total germination was determined under laboratory conditions, as well as the time required for the seeds to reach 50% germination (T50) and the total number of seeds that remained hard at the end of the experiment. The percentage of emerged seedlings and their vegetative growth was evaluated for 21 days after sowing. Results: The seeds of all species evaluated showed a high physiological quality at the time of harvest. Scarification with LN improved germination, emergence and vegetative growth in the species Desmodium scorpiorus, Teramnus labialis, Neonotonia wigthii and Phueraria phaseoloides. Conclusions: Dormancy was effectively overcome in the seeds of the species D. scorpiorus, T. labialis, N. wigthii and P. phaseoloides. It was possible to increase the percentage and speed of germination and emergence, managing to obtain plants with greater vegetative growth during the first 21 days after sowing.

Iron(III)-polymaltose pharmaceutical ferritin analogue Ferrifol® was investigated by high resolution transmission electron microscopy (HRTEM), X-ray diffraction, thermogravimetry, electron magnetic resonance (EMR) spectroscopy, direct current magnetization measurements and 57Fe Mössbauer spectroscopy to get novel information about the structural arrangement of the iron core. The Ferrifol® Mössbauer spectra measured in the range from 295 K to 90 K demonstrated non-Lorentzian two-peak pattern. These spectra were better fitted using a superposition of 5 quadrupole doublets with the same line width. The obtained Mössbauer parameters were different and an unusual line broadening with temperature decrease was observed. Measurements of the Ferrifol® Mössbauer spectra from 60 K to 20 K demonstrated a slow decrease of magnetic relaxation in the iron core. Zero-field-cooled and field-cooled magnetization measurements revealed a blocking temperature at ~33 K and a paramagnetic state of the Ferrifol® iron core at higher temperatures. Isothermal magnetization measurements at 5 K show that the saturation magnetic moment is ~0.31 emu/g. X-band EMR spectroscopy measurements revealed the presence of different magnetic species in the sample. Transmission electron microscopy demonstrated that the size of the iron cores in Ferrifol® is in the range 2–6 nm. The lattice periodicity in these iron cores, measured on the HRTEM images, vary in the range 2.2–2.7 Å. This can be best understood as sets of close packed O(OH) layers in ferrihydrite cores without long range correlation. © 2020 Elsevier Inc.

QC 20211124

Pedicle freezing using liquid nitrogen has been used increasingly in Japan in the last decade for the treatment of long bone tumors with good results. We describe our case of a recurrent chondrosarcoma of the proximal humerus treated with pedicle freezing of the entire osteoarticular segment due to involvement of the metaepiphyseal aspect. A late traumatic fracture occurred 8 months after surgery. Osteosynthesis was done with good union

This study presents surface nitriding of 4H-SiC by the irradiation of the fourth harmonics of Nd:YAG laser pulses in liquid nitrogen. A nitride layer with a depth of 1 mu m is formed on the irradiated area. The irradiated area has a bumpy morphology. On the other hand, we also find a nitride layer with a smooth surface morphology in the outside of the irradiated area. The concentration of nitrogen is dependent on the laser fluence, and is 1-5%. The diffusion coefficient of nitrogen, which is deduced from the depth profile of the nitrogen number density, is much greater than the diffusion coefficient in solid SiC, suggesting the transport of nitrogen in melted SiC. Considering the fact that SiC does not have a melted state at the atmospheric pressure, it is revealed by the present work that the melted SiC is realized transiently with the help of the high pressure driven by the laser irradiation.

Effects of air thawing (AT), refrigerator thawing (RT), water immersing thawing (WIT), lotic water thawing (LWT), and microwave thawing (MT) on the quality of swimming crab by liquid nitrogen freezing were investigated. The highest thawing loss was recorded for MT sample (2.70%) followed by AT (2.22%), WIT (1.97%), and LWT (1.52%), while RT had the lowest value (1.06%). RT sample had the lowest TBARS (0.34 mg/kg) and the highest sensory (8.60) score closer to those for fresh meat, but MT sample had the highest TBARS (0.66 mg/kg) with the lowest sensory score (7.83). Besides, microstructural changes indicated that MT induced larger gaps between muscle fibers and broken more muscle fiber bundles than the other methods, while RT had the least negative role on the microstructure of crab meat. Overall, RT could be recommended as a suitable method for preserving the quality of frozen swimming crab.

This paper presents a novel indirect cryogenic cooling system, employing liquid nitrogen (LN2) as a coolant for machining the difficult-to-cut ASTM F-1537 cobalt-chromium (CoCr) alloy. The prototype differs from the already existing indirect cooling systems by using a modified cutting insert that allows a larger volume of cryogenic fluid to flow under the cutting zone. For designing the prototype analytical and finite element, thermal calculations were performed; this enabled to optimize the heat evacuation of the tool from the rake face without altering the stress distribution on the insert when cutting material. Turning experiments on ASTM F-1537 CoCr alloys were performed under different cutting conditions and employing indirect cryogenic cooling and dry machining, to test the performance of the developed system. The results showed that the new system improved surface roughness by 12%, and cutting forces were also reduced by 12% when compared with the existing indirect cryogenic cooling technique.

The availability of bioresources is a precondition for life science research, medical applications, and diagnostics, but requires a dedicated quality management to guarantee reliable and safe storage. Anecdotal reports of bacterial isolates and sample contamination indicate that organisms may persist in liquid nitrogen (LN) storage tanks. To evaluate the safety status of cryocollections, we systematically screened organisms in the LN phase and in ice layers covering inner surfaces of storage tanks maintained in different biobanking facilities. We applied a culture-independent approach combining cell detection by epifluorescence microscopy with the amplification of group-specific marker genes and high-throughput sequencing of bacterial ribosomal genes. In the LN phase, neither cells nor bacterial 16S rRNA gene copy numbers were detectable (detection limit, 102 cells per ml, 103 gene copies per ml). In several cases, small numbers of bacteria of up to 104 cells per ml and up to 106 gene copies per ml, as well as Mycoplasma, or fungi were detected in the ice phase formed underneath the lids or accumulated at the bottom. The bacteria most likely originated from the stored materials themselves (Elizabethingia, Janthibacterium), the technical environment (Pseudomonas, Acinetobacter, Methylobacterium), or the human microbiome (Bacteroides, Streptococcus, Staphylococcus). In single cases, bacteria, Mycoplasma, fungi, and human cells were detected in the debris at the bottom of the storage tanks. In conclusion, the limited microbial load of the ice phase and in the debris of storage tanks can be effectively avoided by minimizing ice formation and by employing hermetically sealed sample containers.

Objective: The form of human fungal sinusitis that most closely approximates the disease occurring in the dog is chronic erosive non-invasive fungal sinusitis. This disease is characterized by final destruction of bone in the absence of tissue invasion by the fungus and requires both removal of fungal plaques, necrotic tissue and medical therapy with antifungals. Remarkably, these fungal plaques are white indicated that asexual development does not proceed in the patients. Immune response in SNA infections has been studied via biopsy and cytokine profiling as well as transcriptomic analysis of the host tissue. However, a transcriptomic study of this fungal pathogen growing in patients causing a non-invasive infection has never being performed. We obtained fungal plaques directly from canine patients suffering from SNA and characterize the transcriptome of the causative fungus A. fumigatus in order understand gene expression in the context of the host and particularly in the field of in-host adaptation Methods: Four different fungal plaques were isolated from dogs suffering from SNA. After surgical removal using endoscope or trephination part of fungal plaques were immediately frozen in liquid nitrogen and stored at -80°C for RNA isolation and sequencing. RNA isolation was performed using RNeasy Mini Kit® from Qiagen and sequencing was performed by ServiceXS (Leiden, The Netherlands). RNA-seq analysis involved quality check with fastQC. Cleaning and trimming of reads with Fastx-toolkit. Kallisto was used for transcript quantification(TPM) with A. fumigatus Af293 (AspGD) as reference. For functional characterization of the transcriptome, highly variable expressed genes between samples were removed, and 3 subjective levels of expression were established: low (1 to 39.8 TPM), median (39.8 to 1584.8 TPM) and high (1584.8 to 79432.8 TPM), for each group an enrichment analysis was performed. Additionally a more targeted categorization of the transcriptome was done using pu

Konstruktionsbränder kan idag orsaka stora problem för räddningstjänsten. Släckningsarbeten vid konstruktionsbränder brukar idag involvera släckmedel som bygger på vattenbaserade medel. Detta medför att primära skador kan begränsas, men istället uppstår problemet med sekundära skador som mögel eller vattenskador. Idag finns det flertalet släckmedel som används men det finns inga dokumenterade tillfällen där flytande kväve och/eller koldioxid används vid konstruktionsbränder. Branschen har istället funnit användningsområden för flytande kväve vid gruvbränder med flertalet lyckade insatser. Flytande kväve och koldioxidsläckare är båda kylande släckmedel som vid användning uppnår mycket låga temperaturer. Släckmedlen släcker på liknande sätt, båda kyler till en viss del, men den primära släckkällan är kvävning. Flytande kväve får en avsevärd volymutveckling vid fasövergång från flytande till gas. Gasen tränger undan syret i den brandhärjade konstruktionen och kan därmed släcka branden. Koldioxid verkar på samma sätt, kvävande, men i detta fall övergår den kondenserade gasen till fast fas (torr-is) vid aktivering som sedan sublimerar till gas och kväver branden. För att undersöka släckmedlens förmåga att bekämpa konstruktionsbränder samt återantändningsskyddet vid användning, har åtta konstruktioner byggts. De fristående konstruktionerna ska efterlikna ett regelfack från en väggkonstruktion. Vid försöken har fyra konstruktioner använts till att undersöka flytande kväve och fyra konstruktioner för att undersöka koldioxid. Av dessa åtta användes två som testkonstruktioner i syftet att bestämma metod för applicering av släckmedel och anläggning av brand i konstruktionen. För att anlägga en brand i konstruktionerna antändes de i det nedre högra hörnet med hjälp av en propanbrännare. Vid fyra försök applicerades släckmedlen i mitten av konstruktionen i ett hål som borrats för att nå innandömet. Vid de andra två konstruktionerna applicerades släckmedlen vid hålet där branden, Today structural fires can cause big problems for the rescue services. Extinguishing structural fires usually depends on methods involving water based extinguishers. These methods entails that the primary damages can be limited although secondary damages like mold or water damage may arise. Today there are several fire extinguishers that are used in the industry but few documented occasions have been found where liquid nitrogen or carbon dioxide is used on structural fires. Liquid nitrogen has long been used for mining fires with success. What liquid nitrogen and carbon dioxide in extinguishers have in common is that they are both cooling agents which upon activation reach very low temperatures. These extinguishing agents both put out a fire in a similar way, they both chill when applied, but that is not the primary source. The primary source of extinguishing comes by suffocating the fire by removing all the surrounding oxygen. The volumetric growth of gas between phase transitions displaces the oxygen present in the fire ravaged construction and thereby extinguishes the fire. Eight constructions were built to test these extinguishing agents and their potential for extinguishing construction fires. The purpose of these constructions was to simulate one part of an entire wall. To perform these tests, four out of the eight constructions were used to examine liquid nitrogen and the other four were used for carbon dioxide fire extinguishers. Two constructions were used as test constructions with the purpose to test different methods for the extinguishing agents as well as setting fire to the construction. A propane burner was used in the lower right corner of the construction to ignite it. The extinguishing agents were applied to the center of the constructions in four tests. In two tests the extinguishing agents were directed at the base of the fire in the lower right corner. A total of thirty thermocouples were used, divided evenly among the six tests that recorded da

Cryopreservation of biological materials is predominantly done using liquid nitrogen, and its application involves high maintenance costs and the need for periodical refilling of liquid nitrogen. Stable storage in mechanical freezers at −80C would eliminate these issues and allow for shipment of frozen specimens using dry ice. In this work, the possibility of increasing the storage temperature of cryopreserved samples to −80C by using combinations of DMSO and sucrose has been studied. Preservation efficacy was studied by measuring stability of liposomes encapsulated with carboxyfluorescein during storage at −150, −80 and −25C for up to three months. Thermal and molecular mobility properties of the different DMSO-sucrose formulations were measured using differential scanning calorimetry, whereas hydrogen bonding interactions of the formulations were probed by Fourier transform infrared spectroscopy. It was found that addition of sucrose to DMSO solutions increases the Tg, and decreases molecular mobility in the glassy state at a particular temperature. Although it was expected that storage above or close to Tg at −80C would affect liposome stability, stability was found to be similar compared to that of samples stored at −150C. Higher molecular mobility in the glassy state could not be associated with faster CF-leakage rates. Distinct differences in storage stability at −25C, far above Tg, were found among the sucrose/DMSO formulations, which were explained by the differences in permeability of sucrose and DMSO resulting in different levels of osmotic stress in the formulations.

Superconducting fault current limiters (SFCLs) are required to return to the superconducting state within the proper time (recovery time) after limiting a fault current according to a relay operation scheme in a power system. In order to apply SFCLs to power systems, the recovery time is important property and deeply depends on the heat transfer property of the heated surface of the superconducting tape (normal conducting state) to liquid nitrogen. It has been confirmed that REBCO tapes with various shaped fins or PTFE coating improved cooling property. In this paper, to clear the mechanism of cooling property improvement of fins or PTFE coating, boiling phenomena on REBCO tapes with some types of fins or PTFE coating was observed by use of a high-speed video camera. The influence on the cooling improvement property of cooling fins and PTFE coating was discussed according to the photographical view of the boiling phenomenon.

Obtaining high quality RNA is the first step for gene expression analysis. However, the low stability of this molecule and high presence of contaminants such as RNases, proteins and polysaccharides may trouble extractions. Fungi cell wall composition is highly diverse; therefore optimizing RNA extraction procedures is necessary when studying specific organisms. In this study, different methods of tissue homogenization (liquid nitrogen and lyophilization) and RNA extraction (Trizol, CTAB and RNeasy mini kit) were assessed with a native ascomycete, Xylaria sp. RNA purity, concentration and integrity were determined by spectrophotometry and electrophoresis. In addition, a set of housekeeping gene primers was designed targeting the β-tubulin gene. The primers were used to determine if the RNA extracted allowed RT-PCR amplification. It was demonstrated that homogenization of tissue by lyophilization allowed higher yields of RNA regardless of the extraction protocol used, however, the RNA integrity was affected. The higher RNA purity was obtained using CTAB and the higher yields using the RNeasy mini kit. The extracted RNA is amplifiable by RT-PCR regardless of the homogenization and extraction methodology used. However, it is recommended to homogenize the tissue with liquid nitrogen and to extract RNA with the RNeasy mini kit due the shortness and efficiency of these protocols., La extracción de ARN de calidad constituye el primer paso para el análisis de la expresión génica. Sin embargo, su obtención no es sencilla debido a la susceptibilidad de esta molécula a la presencia de contaminantes como ARNasas, proteínas y polisacáridos. Adicionalmente, debido a la diversa composición de la pared celular de los hongos se requiere optimizar los procesos de extracción de ARN para organismos específicos. Este estudio evalúo el uso de diferentes metodologías de homogeneización de tejido (nitrógeno líquido y liofilización) y extracción de ARN (Trizol, CTAB y RNeasy mini kit) a partir del hongo nativo ascomiceto Xylaria sp. Se determinó la pureza, concentración e integridad del ARN obtenido por medio de espectrofotometría y electroforesis. Adicionalmente, se diseñaron cebadores de referencia para el gen β-Tubulina a partir del alineamiento de secuencias de este gen obtenidas de diferentes ascomicetes. Estos cebadores fueron utilizados para evaluar si el ARN extraído es amplificable mediante RT-PCR. Se determinó que la homogeneización de tejido por medio de liofilización generó mayores rendimientos de extracción independientemente del protocolo de extracción utilizado; sin embargo, éstos alteraron la integridad del ARN. Se obtuvo un ARN con mayor pureza con el protocolo CTABy un mayor rendimiento con el RNeasy mini kit. Los resultados indican que el ARN extraído, independientemente de la metodología de homogeneización y extracción utilizada, es amplificable mediante RT-PCR. No obstante, se recomienda homogeneizar el tejido con nitrógeno líquido y extraer con RNeasy mini kit por la brevedad del protocolo de extracción y calidad obtenida.

Insufficient bone union is the occasional complication of biomechanical reconstruction after malignant bone tumor resection using temperature treated tumor bearing bone; freezing, pasteurization, and autoclaving. Since bone morphogenetic protein (BMP) plays an important role in bone formation, we assessed the amount and activity of BMP preserved after several temperature treatments, including -196 and -73 °C for 20 min, 60 and 100 °C for 30 min, 60 °C for 10 h following -80 °C for 12 h as an allograft model, and 4 °C as the control. The material extracted from the human femoral bone was treated, and the amount of BMP-7 was analyzed using an enzyme-linked immunosorbent assay. Then, the activity of recombinant human BMP-7 after the treatment was assessed using a bioassay with NIH3T3 cells and immunoblotting analysis to measure the amount of phospho-Smad, one of the signaling substrates that reflect the intracellular reaction of BMPs. Both experiments revealed that BMP-7 was significantly better preserved in the hypothermia groups. The percentages of the amount of BMP-7 in which the control group was set at 100% were 114%, 108%, 70%, 49%, and 53% in the -196, -73, 60, 100 °C, and the allograft-model group, respectively. The percentages of the amount of phospho-Smad were 89%, 87%, 24%, 4.9%, and 14% in the -196, -73, 60, 100 °C, and the allograft-model group, respectively. These results suggested that freezing possibly preserves osteoinductive ability than hyperthermia treatment. © 2011 Elsevier Inc. All rights reserved.

In vitro shoot tips of the blackberry cultivar 'Čačanska Bestrna' were cryopreserved using the droplet vitrification technique. Upon loading (30 min) in a solution of 1.9 M glycerol and 0.5 M sucrose, the explants were dehydrated for 40 min on ice with the PVS A3 vitrification solution (glycerol 37.5%, dimethyl sulfoxide 15%, ethylene glycol 15% and sucrose 22.5%) and for 40 min at room temperature with the PVS3 solution (glycerol 50% and sucrose 50%). They were subsequently frozen in individual microdroplets of vitrification solution, by direct immersion in liquid nitrogen (LN), and kept therein for 2, 4, 8 and 24 h. The explant rewarming was performed in an unloading solution (0.8 M sucrose) for 30 min at room temperature. The duration of LN exposure did not exert significant effects on the survival and regrowth of explants in both types of vitrification solutions. The survival and regrowth of cryopreserved shoot tips dehydrated with PVS3 solution ranged between 90-95% and 80-90%, respectively. However, dehydration with PVS A3 resulted in a lower survival rate (80-90%) and a considerably lower regrowth rate (55-65%) of explants. Monitoring the shoots regenerated in the in vitro culture revealed their normal capacity for multiplication and rooting in comparison with the controls, which fully confirms the purpose of cryopreservation in the long-term preservation of plant material., Vrhovi in vitro izdanaka sorte kupine Čačanska bestrna su krioprezervirani primenom tehnike "droplet" vitrifikacija. Po završenom osmotskom tretmanu (30 min) u rastvoru sa 1,9 M glycerolom i 0,5 M saharozom, eksplantati su dehidrirani 40 min na ledu vitrifikacionim rastvorom PVS A3 (glicerol 37,5%, dimetil sulfoksid 15%, etilen glikol 15% i saharoza 22,5%) ili 40 min na sobnoj temperaturi PVS3 rastvorom (glicerol 50% i saharoza 50%). Eksplantati postavljeni u kapljice vitrifikacionog rastvora na aluminijumskoj foliji su direktno uranjani u tečni azot gde su držani 2, 4, 8 i 24 h. Osmotska rehidracija je vršena 30 min u rastvoru sa 0,8 M saharozom, na sobnoj temperaturi. Dužina čuvanja eksplantata u tečnom azotu nije imala značajan uticaj na procenat preživljavanja i regeneracije eksplantata dehidriranih sa oba vitrifikaciona rastvora. Preživljavanje i regeneracija eksplantata koji su dehidrirani sa PVS3 su iznosili 90-95% i 80-90%, resp. Međutim, dehidracija sa PVS A3 je rezultirala nižim procentima preživljavanja (80-90%) i regeneracije (55-65%) eksplantata. Praćenjem regenerisanih izdanaka u in vitro kulturi utvrđeno je da oni imaju normalan kapacitet za multiplikaciju i ožiljavanje u poređenju sa kontrolnim izdancima čime je u potpunosti potvrđena svrha krioprezervacije za dugotrajno čuvanje biljnog materijala.

During the past two decades, hydraulic fracturing has significantly improved oil and gas production from shale and tight sandstone reservoirs in the United States and elsewhere. Considering formation damage, water consumption, and environmental impacts associated with water-based fracturing fluids, efforts have been devoted to developing waterless fracturing technologies because of their potential to alleviate these issues. Herein, key theories and features of waterless fracturing technologies, including Oil-based and CO2 energized oil fracturing, explosive and propellant fracturing, gelled LPG and alcohol fracturing, gas fracturing, CO2 fracturing, and cryogenic fracturing, are reviewed. We then experimentally elaborate on the efficacy of liquid nitrogen in enhancing fracture initiation and propagation in concrete samples, and shale and sandstone reservoir rocks. In our laboratory study, cryogenic fractures generated were qualitatively and quantitatively characterized by pressure decay tests, acoustic measurements, gas fracturing, and CT scans. The capacity and applicability of cryogenic fracturing using liquid nitrogen are demonstrated and examined. By properly formulating the technical procedures for field implementation, cryogenic fracturing using liquid nitrogen could be an advantageous option for fracturing unconventional reservoirs.

Oil palm (Elaeis guineensis Jacq.) has benefited little from molecular marker technologies although the long generation time and the unpredictable variations due to allogamy make it a high priority for improving breeding efficiency. Progress would require an efficient, low cost and high-throughput deoxyribonucleic acid (DNA) extraction method adapted for oil palm. A method for genomic DNA extraction from oil palm leaves that is simple and cost-effective was developed without the use of liquid nitrogen. A260/280 ratios between 1.987 and 2.078 were obtained. Furthermore, we could demonstrate that nucleic acid concentration and yield were inversely proportional to the pH and ionic strength of the solvent. The measured values varied significantly between 572 ng/µl and 496 ng/µl. DNA extracted with this method is stable and can be reproducibly amplified by PCR.

The DNA extraction free polysaccharides, polyphenols, plant protein and RNA is the initial step to several studies in molecular biology. There are various methods of extracting specific DNA of sugar cane (Saccharum officinarum), however, are time consuming and expensive equipment and reagents used. The aim of this study was to optimize a fast, efficient and inexpensive protocol for extracting DNA from leaves of S. officinarum. The variables evaluated were yield, purity, integrity and functionality of DNA purified from leaves of sugarcane 6 months old. Techniques spectrophotometry, agarose gel electrophoresis and molecular markers to evaluate the above variables were used. The performance variables (mg/g) and purity (A260:280 and A260:230) the extracted DNA showed highly significant differences (p˃ 0.05) protocol I. The best results were obtained with the protocol interaction I +N2, DNA yield 1.17 mg/g and 1.95 and 1.91 purities (A260:280 and A260:230). Functionality DNA by PCR amplification with the RAPD markers and TRAP bands sharp profiles generated good quality and easy to interpret. The use of the protocol I+N2 for extracting DNA from S. officinarum to obtain high yields of DNA with optimal quality and purity for applications of molecular markers is recommended., La extracción de DNA libre de polisacáridos, polifenoles, proteínas y RNA de plantas constituye el paso inicial para diversos estudios en Biología molecular. Existen diversos métodos de extracción de DNA específicos para caña de azúcar (Saccharum officinarum), sin embargo, consumen mucho tiempo y utilizan reactivos y equipos costosos. El objetivo del presente estudio fue optimizar un protocolo rápido, eficiente y de bajo costo para extraer DNA de hojas de S. officinarum. Las variables evaluadas fueron rendimiento, pureza, integridad y funcionalidad del DNA purificado de hojas de caña de azúcar de 6 meses de edad. Se utilizaron técnicas de espectrofotometría, electroforesis en geles de agarosa y marcadores moleculares para evaluar las variables anteriores. Las variables rendimiento (mg/g) y pureza (A260:280 y A260:230) del DNA extraído mostraron diferencias altamente significativas (p˃ 0.05) con el protocolo I. Los mejores resultados se obtuvieron con la interacción del protocolo I +N2, con un rendimiento de DNA de 1.17 mg/g y purezas de 1.95 y 1.91 (A260:280 y A260:230). La funcionalidad del DNA por amplificación por PCR con los marcadores RAPD y TRAP generaron perfiles de bandas nítidas de buena calidad y de fácil interpretación. Se recomienda el uso del protocolo I +N2 para la extracción de DNA de S. officinarum para obtener elevados rendimientos de DNA con calidad y pureza óptima para aplicaciones de marcadores moleculares

La dinámica del mercado en los últimos años ha llevado a Cryogas a optimizar sus costos de producción y evitar agotados, maximizando el servicio al cliente y la rentabilidad de sus productos -- La realización este proyecto es con el objetivo de identificar la metodología propuesta genera un pronóstico acertado frente a los métodos y resultados utilizados actualmente y mejorar los costos productivos mediante una producción con una mejor eficiencia energética -- La investigación parte de la identificación de variables que afecta la demanda de los productos con mayor irregularidad, para cuantificar y generar entradas para los diferentes modelos de redes neuronales -- Se realizaron varios pronósticos con diferentes modelos cuyos resultados se comparan con datos de control para seleccionar el de mejor desempeño y mayor exactitud -- Los resultados obtenidos con el modelo de pronóstico de mejor desempeño se comparan con realidad y el método usado actualmente por Cryogas para identificar el mejor -- Los resultados obtenidos permiten una mejora en los procedimientos de Cryogas que impactaran positivamente la rentabilidad de la compañía, se tendrán parámetros de generación de pronósticos basados en criterios sólidos y se buscara eliminar la subjetividad en esta actividad