Band Intensity Research Articles

Molecular sensitization profile to grass and olive pollens in Portugal.

Background. Grass and olive pollens have overlapping pollination periods and are common allergens in the Iberian Peninsula. The objective is to determine the sensitization pattern to major Phleum pratense and Olea europaea pollens in the Portuguese population with pollen allergic rhinitis (AR) using molecular allergen diagnosis (MAD). Methods. Seasonal AR patients (≥ 12 years), with positive skin prick tests (SPT) to Phleum and Olea were recruited from 16 centers. Using ALEX2, specific IgE to Phl p1, Phl p2, Phl p5, Phl p6, Phl p7, Phl p 12, Ole e1, Ole e7 and Ole e9 were determined. Immunoblotting of Olea allergic patients was performed. Results. Included 175 patients (55.4% female; mean age 31.6 ± 13.3 years; 85.7% adults; 40% asthmatic, Coast 28%/Inland 72% and North 29.1%/Centre 20.6%/South 50.3%). Considering Phleum MAD, 85.7% were sensitized to Phl p1, 45.7% to Phl p2, 50.3% to Phl p5, 45.7%, to Phl p6, 10.9% to Phl p7 and 22.9% to Phl p12. Sensitization to Ole e1 was found in 56.6%, to Ole e7 in 1.7% and Ole e9 in 3.4% patients. Sensitization to Phl p7 was more frequent in asthmatics (17.4% vs 6.6%; p = 0.044). Sensitization to Phl p5, Phl p6, Phl p12 and Ole e1 was more frequent in inland. Regarding sensitization patterns: 53.1% patients were sensitized to both species genuine´ sIgE, 38.3% to Phleum and 3.4% only to Olea species' sIgE. Immunoblotting of Olea allergic patients showed a high intensity band that may correspond to Ole e12. Conclusions. MAD showed "genuine" Grass and Olea sensitization in approximately 50% of our patients.

Spectroscopic studies on natural fluorapatites irradiated with 10 MeV electrons

Fluorapatites are one of the candidate matrices for hosting the nuclear waste from molten salt reactors. To assess their radiation stability and long-term performance, natural analogue study approach was undertaken. Naturally occurring fluorapatites containing with carbonate substitutions were irradiated with 10 MeV electron beam radiation for doses 20 MGy. X-ray diffraction, Raman and Fourier Transform infrared spectroscopy show no evidence of structural degradation or phosphate condensation. However, a change in the intensity of ν3 Phosphate Raman bands was observed indicating that the phosphate tetrahedra is affected by the electron beam consistent with the displacement cross-section calculations for each constituent element. Overall, the study confirmed that fluorapatite possess good structural stability against electron radiation upto 20 MGy.

Wavelength-tunable photoluminescence of CsPbBr3 microcrystal via in situ halogen doping

Lead halide perovskite semiconductors have received significant attention in recent years as promising candidates for optoelectronic applications. Their controllable bandgap in nanostructures (nanocrystals, nanowires) has been widely and successfully investigated. Intentionally manipulating the atomic behavior with dopants in their macroscopic structure with high quality and stability is still challenging. We studied the crystal structure and photoluminescence (PL) behavior of the anion (Cl) doped CsPbBr3 microcrystals. The doped microcrystal with a low doping concentration has shown a large wavelength-tunable PL emission from 535 nm to 457 nm. Two separate emission peaks (blue and green) are carefully studied in the excitation power dependent PL spectra. The doping and excitation endow the perovskite microcrystal adjustable PL emission band and peak intensities, which may serve as a new degree of manipulation freedom in the color-tunable display and functional optoelectronics.

Manifestation of molecular vibrations of polymers in thermoluminescence of nanocomposites

An experimental and theoretical study of the thermoluminescence (TL) of a PDHS/MCM-41 nanocomposite with the introduction of a polymer (poly-di-n-hexylsilane) (PDHS) into MCM nanopores has been carried out in the temperature range 5–150K. TL curve consists of a very narrow intense band and wider less intense band. In the nananocomposite there is a strong shift of the curve toward low temperatures compared to the curve of the film and a significant narrowing of the bands. The calculations used the model of non-adiabatic transitions. Results show a significant role of molecular vibrations in the formation of the TL curve of a nanocomposite.

Structural Changes in 2-Acetoxybenzoic Acid (2ABA) in the Presence of Various Solvents: A Quantum Chemical and Spectroscopic Study

2-Acetoxy benzoic acid (2ABA) can produce structural changes in the molecule when dissolved in different solvents depending on factors such as solvent polarity, Hydrogen bonding and solvent interactions. Therefore, quantum chemical calculations were performed using Gaussian 09: AS64L-G09RevD.01 software. The structural changes of the 2ABA molecule in the presence of solvents were recorded by Fourier Transform Infrared (FT-IR) Spectroscopy in the 4000-0 cm-1 range. Additionally, Nuclear Magnetic Resonance (NMR) Spectroscopy was employed to examine changes in chemical shift values associated with the dissolution of the molecule. In another phase of the study, the geometric parameters of the optimized molecules, atomic charges, intensities of the vibrational bands, and vibrational frequencies were calculated using Density Functional Theory (DFT). These calculations were performed at the DFT/B3LYP level with the LanL2DZ basis set, providing a detailed analysis of solvent effects at the molecular level. This study offers significant insights into the interactions of solvent environments with molecular structures and contributes to potential drug development processes.

Research on Evolution of Relevant Defects in Heavily Mg-Doped GaN by H Ion Implantation Followed by Thermal Annealing.

This study focuses on the heavily Mg-doped GaN in which the passivation effect of hydrogen and the compensation effect of nitrogen vacancies (VN) impede its further development. To investigate those two factors, H ion implantation followed by thermal annealing was performed on the material. The evolution of relevant defects (H and VN) was revealed, and their distinct behaviors during thermal annealing were compared between different atmospheres (N2/NH3). The concentration of H and its associated yellow luminescence (YL) band intensity decrease as the thermal annealing temperature rises, regardless of the atmosphere being N2 or NH3. However, during thermal annealing in NH3, the decrease in H concentration is notably faster compared to N2. Furthermore, a distinct trend is observed in the behavior of the blue luminescence (BL) band under N2 and NH3. Through a comprehensive analysis of surface properties, we deduce that the decomposition of NH3 during thermal annealing not only promotes the out-diffusion of H ions from the material, but also facilitates the repair of VN on the surface of heavily Mg-doped GaN. This research could provide crucial insights into the post-growth process of heavily Mg-doped GaN.

Simulation Computation of Two-dimensional Hexagonal Honeycomb Photonic Crystals Energy Band Structure Based on COMSOL

This study employs COMSOL software, integrating the plane wave expansion method and finite element method, to simulate and analyze the energy band structure of two-dimensional hexagonal honeycomb photonic crystals. By setting parameters and conducting scans, this paper not only maps out the electric field intensity and energy band distribution but also discovers a significant enhancement of electric field intensity at the lattice's high symmetry points, indicating a higher likelihood of electromagnetic waves' presence at these points. Furthermore, the notable energy gaps between the second and third energy bands provide directions for subsequent research. The findings of this study are of significant value for research and development in optoelectronic integration and communication, demonstrating an effective comprehensive method for analyzing the energy band structure of two-dimensional hexagonal honeycomb photonic crystals.

The pressure dependence of the experimentally-determined line intensity and continuum absorption of pure CO2 in the 1.6µm region

Fourier-transform measurements of pure CO2 spectra in the 1.6 µm region covering bands from the ground state to the 30011, 30012, 30013, and 30014 states at ambient temperature and 212 K with pressures up to 1 atm have been recorded. The measured spectra have been multispectrum-fitted with the Hartmann-Tran model with first order line-mixing taken into account. In the fits, a linear decrease of the line intensities with increasing pressure was introduced. From the fitted baselines, the self-continuum, which complements the contribution of the local lines within +/− 25 cm−1, was determined for the two strongest bands, 30012–00001 and 30013–00001. The depleted intensity was found to be transferred to the continuum for both temperatures. The intensity in the continuum at 1 atm was about 1 % of the total band intensity for ambient temperature and about 3 % at 212 K. For both temperatures, the average depleted intensity/continuum area was found in excellent agreement with values estimated from the second virial coefficient. From these results, a new spectroscopic database with pure CO2 line profile parameters was produced, with systematic line intensity uncertainties well below 0.1 %.Retrieval simulations for the CO2 1.6 µm and 2 µm bands measurements, planned with the future CO2M mission, similar to the OCO mission, were carried out to assess the impact of intensity depletion and continuum. The impact of the continuum was larger than that of the depletion and larger for the 2 µm band than for the 1.6 µm band, with a substantial column error of 2 % for the 2 µm band when omitting both, depletion and continuum.The findings regarding pressure-dependent intensity and continuum may be applicable to other in-band continua showing similarity to the monomer band in shape and position. The new results may increase the knowledge on the physical nature of continua.

A one-process production of completely biotinylated proteins in a T7 expression system.

Streptavidin is a tetrameric protein with high specificity and affinity for biotin. The interaction between avidin and biotin has become a valuable tool in nanotechnology. In recent years, the site-specific biotin modification of proteins using biotin ligases, such as BirA, has attracted attention. This study established an in vivo method for achieving the complete biotinylation of target proteins using a single plasmid co-expressing BirA and its target proteins. Specifically, a biotin-modified protein was produced in Escherichia coli strain BL21(DE3) using a single plasmid containing genes encoding both BirA and a protein fused to BirA's substrate sequence, Avitag. This approach simplifies the production of biotinylated proteins in E. coli and allows the creation of various biotinylated protein types through gene replacement. Furthermore, the biotin modification rate of the obtained target protein could be evaluated using Native-PAGE without performing complicated isolation operations of biotinylated proteins. In Native-PAGE, biotin-modified proteins and unmodified proteins were confirmed as clearly different bands, and it was possible to easily derive the modification rate from the respective band intensities.

Effect of enzymatic modification on the structure and rheological properties of diluted alkali-soluble pectin fraction rich in RG-I

This study focuses on pectin covalently linked in cell walls from two sources, apples and carrots, that was extracted using diluted alkali, and it describes changes in the rheological properties of diluted alkali-soluble pectin (DASP) due to enzymatic treatment. Given DASP’s richness of rhamnogalacturonan I (RG-I), RG-I acetyl esterase (RGAE), rhamnogalacturonan endolyase (RGL), and arabinofuranosidase (ABF) were employed in various combinations for targeted degradation of RG-I pectin chains. Enzymatic degradations were followed by structural studies of pectin molecules using atomic force microscopy (AFM) as well as measurements of rheological and spectral properties. AFM imaging revealed a significant increase in the length of branched molecules after incubation with ABF, suggesting that arabinose side chains limit RG-I aggregation. Structural modifications were confirmed by changes in the intensity of bands in the pectin fingerprint and anomeric region on Fourier transform infrared spectra. ABF treatment led to a decrease in the stability of pectic gels, while the simultaneous use of ABF, RGAE, and RGL enzymes did not increase the degree of aggregation compared to the control sample. These findings suggest that the association of pectin chains within the DASP fraction may rely significantly on intermolecular interactions. Two mechanisms are proposed, which involve side chains as short-range attachment points or an extended linear homogalacturonan conformation favoring inter-chain interactions over self-association.

Optical properties of nanocomposites based on polypropylene modified by nanoparticles of oxide compounds

The optical properties in UV, visible and near IR spectral regions for nanocomposites based on polypropylene modified by nanoparticles of oxide compounds ZrO2, Al2O3, SiO2, MgO, TiO2, ZnO were studied. A shift of the main optical absorption edge to the short-wave region upon modification by dielectric nanoparticles (MgO, ZrO2, and Al2O3) was established. The absorption edge shifts to the long-wave region upon the introduction of semiconductor nanoparticles (ZnO, TiO2) and amorphous SiO2 particles. In all spectra, the absorption bands at 1200, 1400, and 1720 nm characterized by overtone vibrations of CH, CH2, and CH3 molecular groups were recorded. OH groups make a certain contribution to the bands at 1400 and 1720 nm. The dependence of the intensity of these absorption bands on the type and concentration of nanoparticles used in the modification of polypropylene was analyzed. X-ray diffraction analysis of the studied nanocomposites was carried out, the formation of β-PP was registered upon modification by Al2O3 nanoparticles. Photoluminescence spectra of nanocomposites were studied. It was found that the introduction of nanoparticles (except SiO2) does not lead to the formation of new luminescence bands in PP.

Preparation and pharmacological evaluation of A3B-type tetraphenyltetrabenzoporphyrins for photodynamic anti-tumor therapy

A series of A3B-type meso-tetraphenyltetrabenzoporphyrin photosensitizers were designed, synthesized and evaluated. All new compounds exhibited an intense Soret band at ∼ 470 nm and three Q bands at ∼ 595, ∼ 648, and ∼ 701 nm. They all had the ability to produce singlet oxygen upon photoexcitation, and photodynamic activities towards human esophageal carcinoma (Eca-109) cancer cells in vitro. Among them, 5 displayed the excellent cytotoxic effect on Eca-109 cells with the cell viability of ∼30 % at the concentration of 0.5 μM under a light dose of 12 J/cm2. 5 also could induce cell apoptosis after laser irradiation, and display superior photodynamic activity towards Eca-109 cells in vivo. Notably, inflammation and nuclear shrinkage of tumors were observed in the 5-PDT group, while no obvious changes were presented in major organs (heart, kidney liver, lung, and spleen) of mice, and the weight of mice were increased steadily during the treatment period. Hence, compound 5 possesses high photodynamic efficacy and good biosafety, and deserves to be considered as a potential photodynamic drug candidate for cancers.

Polarized spectroscopic properties of Tm3+/Ho3+:YPO4 single crystal: A potential gain medium for tunable and ultrafast pulse laser at 2.0 μm

YPO4 crystals co-doped with Tm3+ and Ho3+ ions (Tm3+/Ho3+:YPO4) have been prepared using the high temperature solution method. The crystal structure, electronic band and polarized spectroscopy were characterized. It has intense and broad absorption bands around 800 nm with a full width at half maximum of 14.31 nm and 22.95 nm for π- and σ-polarizations, respectively. Based on Judd-Ofelt theory, relevant parameters about the radiative properties were systematically analyzed. The broad emission bands of Tm3+ and Ho3+ from 1600 to 2300 nm allow wide tunability of laser oscillation. The energy transfer efficiency from Tm3+: 3F4 to Ho3+: 5I7 level in YPO4 crystal was calculated to be 54.59 %. The results show that Tm3+/Ho3+:YPO4 is expected to be applied in tunable and ultrafast pulse laser at 2.0 μm.

Luminescence of CsLa1-хCeхSiS4 thiosilicate solid solution: From STE to Ce3+ emission

A series of single crystals of CsLa1-хСехSiS4 monophasic solid solution (x = 0–1) has been obtained for the first time by high-temperature flux synthesis. Methods of XRD and chemical analysis, absorption and low-temperature (from T = 5 K) luminescent spectroscopy were used. The results of the band scheme calculating using density functional theory correlate with spectroscopy data. One non-elementary d → f emission band of Ce3+ ions is observed in the region of 520 nm in the luminescence spectra at room temperature at any value of the x parameter. The luminescence decay kinetics of Ce3+ ions upon excitation by a pulsed electron beam, X-ray synchrotron radiation or intracenter photoexcitation is characterized by a nanosecond component. As the parameter x increases, the decay time is reduced from 132 ns (x = 0.005) to 0.88 ns (x = 1). The luminescence decay kinetics upon photoexcitation at x = 0.005–0.12 is characterized by monoexponential decay with τ = 31.4 ± 0.2 ns. Concentration quenching of the Ce3+ ion photoluminescence is not observed up to the value of the parameter x = 0.12; it only appears at x = 1. The anomalously short decay time of the Ce3+ ions luminescence in CsCeSiS4 upon both X-ray excitation and photoexcitation is associated with concentration quenching.At temperature 5 K, new intense bands at 408 and 688 nm in addition to the Ce3+ emission band observed in the photoluminescence spectra of nominally pure CsLaSiS4 or at the lowest parameter value x = 0.005. These bands correspond to the luminescence of self-trapped excitons (STE) and defects. With increasing x parameter, the STE emission band is reabsorbed by the absorption of Ce3+ ions and is quenched due to the resonance energy transfer STE → Ce3+ center. Thermoluminescence glow curves of CsLa1-xCexSiS4 irradiated with X-ray at T = 90 K are characterized by several low temperature intense peaks, which indicates a high concentration of charge carrier traps.

Luminescence Dynamics of BaAl2O4:Eu2+ Phosphor.

We studied steady-state and time-resolved photoluminescence of Eu doped BaAl2O4 phosphor. The undoped BaAl2O4 sample shows a dominant blue emission band at ~ 428nm and two secondary maxima at ~ 405 and 456nm due to F-centre and aggregate defects such as F2 -centre. The samples after doping of Eu at 1-5% show additional emission bands at ~ 485 and 518 nm due to Eu2+ centre and a red emission band at ~ 657nm is attributed to Eu3+ centre. The sample doped with 2% of Eu shows anomalous emission having the dominant peak at ~ 494nm. The average luminescence lifetime of the emission band at ~ 428nm in the undoped sample was estimated to be (3.29 ± 0.91) ns. The average luminescence lifetime of this emission band after doping of Eu was found to increase by 102 orders of magnitude. The intensity of the 428nm blue emission band was found to quench after doping of Eu beyond 3%. The concentration quenching effect was attributed to dipole-quadrupole interaction. Further, a non-radiative fluorescence energy transfer mechanism from an extrinsic Eu2+ centre to an intrinsic F-centre is proposed to describe the luminescence dynamics of the samples.

Using salted egg white in steamed bread: Impact on functional and structural characteristics

Steamed bread has long been an important part of Chinese cuisine. This study investigated the effects of salted egg white (SEW) (5, 10, 15, and 20% w/w) on the quality of steamed breads. Findings revealed that SEW notably enhanced the bread's volume and texture, with a 20% inclusion significantly boosting water retention and rheological properties, albeit reducing bread's lightness. In addition, the H-bond absorption band intensity in the Fourier transform infrared spectroscopy (FTIR) analysis showed increased peak intensities with higher SEW levels, indicative of protein structure alterations. X-ray diffraction confirmed the presence of an amylose–lipid complex. Scanning electron microscope (SEM) and Confocal laser scanning microscope (CLSM) imaging depicted a smooth, consistent protein network with SEW addition. Consumer sensory evaluation responded favourably to the SEW15 steamed bread, suggesting its potential for food industry application. Overall, the study considers SEW an effective ingredient for improving steamed bread quality.

Enhanced UVB 311 emission in Sb2O3–SiO2 glasses doped with Gd2O3 and tailored Pb3O4 content for potential phototherapy

This study investigates the enhancement of the sharp 311 nm UVB emission from Gd3+ ions in antimony silicate glass system doped with a fixed concentration of Gd2O3 (1.0 mol%) and varying amounts of red lead (40–10 mol%). The emission spectra revealed an intense sharp UVB band at 311 nm, originating from the 6P7/2 → 8S7/2 transition of gadolinium ions upon excitation at 273 nm. Interestingly, the intensity of this band nearly doubles as the Pb3O4 content decreases from 40 to 10 mol%. Such improvement was attributed to the decomposition of Pb3O4 into various phases that include α-PbO2, β-PbO2 polymorphs, and PbO. Out of these decomposition products, PbO acted as modifiers, reduced phonon losses and consequently enhanced the emission intensity. The decrease in Pb3O4 content is also hypothesized to promote de-clustering of Gd3+ ions within the glass matrix. This de-clustering reduced cross-relaxation losses, further contributed to the observed emission enhancement. In summary, this study demonstrated a successful strategy for boosting the UVB emission from Gd3+ ions in antimony silicate glasses by manipulating the content of Pb3O4.

MODIFICATION OF PINDIGA BENTONITE CLAY WITH DIDODECYLDIMETHYLAMMONIUM BROMIDES SURFACTANT FOR FOUNDRY USE

Bentonite clay from Pindiga, Gombe State, Nigeria, was surface modified with didodecyldimethylammonium bromides (DDAB) by the Base Exchange (cation exchange capacity) method for its possible use in foundries. The surfaces of the unmodified and modified Pindiga bentonite clay were characterised by means of spectroscopic, diffraction, and scanning methods (X-Ray fluorescence spectrometry (XRF)Fourier-transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM).XRF showed that unmodified sample was rich of montmorillonite (MMt) with ca +2 as exchangeable cation, FTIR analysis revealed that unmodified water absorption causes stretching and bending vibrations for hydroxyl groups, with the most intense bands in the low-frequency region, while DDAB organo-bentonites showed slight changes in wave bands, with a strong methyl band and a weak methyl band indicative of long-chain linear aliphatic structure. The basal spacing of the unmodified bentonite sample was 1.52 nm, and after modification with DDAB, it improved to 2.1 nm as determined from the X-ray diffraction (XRD) analysis. Results of the SEM images revealed rougher surfaces with uniformly dispersed small particles of grain-like structures characteristic of the unmodified, while theorgano-modified bentoniterevealed clusters of different sizes and shapes, larger Fe 3+ ions replacing smaller Al 3+ ions at octahedral sites, discontinuous layers enveloping large grains, polygonal growth foams with octahedral and tetrahedral shapes, mixed layers of calcium bentonite, and particle sizes less than 200nm. The study concluded that modified bentonite with didodecyldimethylammonium bromides gives good microstructure, increases rigidity, and improve thermal stability, to the organoclays. Therefore, it is recommended that DDAB bentonite be used as binder for foundries.

Raman spectroscopy‐based molecularly imprinted polymer sensor for sensitive detection of lysophosphatidic acid in serum

AbstractLysophosphatidic acid (LPA) has significant potential as a biomarker for diagnosis of ovarian cancer in female patients because it is present throughout all phases of the illness. Regrettably, there is not a clinically useful test for this biomarker yet. In this work, an ultra‐detection of LPA molecule by Raman spectroscopy‐based molecularly imprinted polymer (MIP) in serum samples is reported. β‐CD was synthesized to facilitate the collection of Raman spectroscopy and combined with MIP to denote it as β‐CD‐MIP for the adsorption of LPA with high sensitivity and selectivity. Linear regression model in serum samples shows peaks at 1100 and 1116 cm−1, respectively. A satisfactory linear fit was seen with LPA concentration log I = 3.7 log C + 1255.74 and with spiked serum log I = 4.6 log C + 327.22, respectively. The literature survey suggests the threshold LPA level in healthy person is 1.50 μM/L whereas the LPA level rises in patients with benign ovarian cancer tumor as 7.90 μM/L. This LPA level rises to 16.99 μM/L in ovarian cancer patients. On the basis of the band intensity, the limit of detection of the β‐CD‐MIP sensor for LPA was recorded as 0.003 μM/L. The binding constant of β‐CD‐MIP for LPA in serum was 0.031–0.003 μM/L, respectively. β‐CD‐MIP gel was optimized, characterized, and successfully applied on spiked serum samples. The findings of this research show that this substrate has a lot of potential for ultradetection of trace amounts of LPA molecule from the serum samples. The MIP sensor is robust, recyclable, efficient, and selective.

Changes in characteristics of spermatogonial stem cells in response to heat stress in stallions

Spermatogonial stem cells (SSCs) are essential for the maintenance of male fertility and survival of species. Environmental conditions, notably heat stress, have been identified as important causes of male infertility and have a negative impact on SSCs. Animals with cryptorchid testes (CT) are optimal models for the study of long-term heat stress-related changes in germ cells. The effect of heat stress on germ cells differs depending on the spermatogenesis stage. Thus, verifying whether the specific phase of spermatogenesis is dependent or independent of heat stress in stallions is important. We evaluated the heat stress-related response of SSCs by comparing the relative abundance of mRNA transcripts and expression patterns of the undifferentiated embryonic cell transcription factor 1 (UTF-1) and deleted in azoospermia-like (DAZL) in the seminiferous tubules of CT and normal testes (NT) of stallions using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), immunofluorescence, and western blotting. We also analyzed the relative abundance of mRNA of different proliferative markers, including minichromosome maintenance 2 (MCM2), marker of proliferation Ki-67 (MKI-67), and proliferating cell nuclear antigen (PCNA). Testicular tissues from four Thoroughbred unilateral cryptorchid postpubertal stallions were used in this study during the breeding season. The relative abundance of the mRNA transcripts of UTF-1 and MCM2 was significantly upregulated in the CT group than that of those in the NT group. In contrast, the relative abundance of the mRNA transcripts of DAZL was significantly downregulated in the CT group than that of those in the NT group. Western blot quantification showed that the relative intensity of UTF-1 protein bands was significantly higher, while that of DAZL protein bands was significantly lower in the CT group than in the NT group. Immunofluorescence studies showed that the number of germ cells immunostained with UTF-1 was significantly higher while immunostained with DAZL was significantly lower in the CT group than that in the NT group. The higher expression level of UTF-1 in the CT group shows that undifferentiated SSCs are not affected by long-term exposure to heat stress. These results also indicate that germ cells after differentiation phase are directly affected by heat-stress conditions, such as cryptorchidism, in stallions.