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Male infertility is an increasingly serious health problem affecting couples of reproductive age. Mutations in axoneme-associated genes cause male infertility. Dynein arm proteins are essential in sustaining normal axonemes and promote flagellar motility. However, the function of DNAH7 in male fertility in vivo remains unclear. Herein, we showed that DNAH7 disruption in humans results in male infertility, which was characterised by multiple morphological abnormalities of sperm flagella. The axoneme structure of the sperm from a DNAH7-deficient patient revealed the loss of inner dynein arms. Moreover, the mitochondria of the sperm flagella detached and dispersed outside the axoneme, leading to abnormalities in the mitochondrial sheath in the mid-piece region. Live birth was achieved via intracytoplasmic sperm injection. Thus, DNAH7 is critical for axoneme and mitochondrial development in human sperm. These findings further clarify the spectrum of DNAH7 biology and provide new insights for diagnosing infertility and treating patients harbouring DNAH7 mutations.

Understanding the surrounding scenes is one of the fundamental tasks in intelligent transportation systems (ITS), especially in unpredictable driving scenes or in developing regions/cities without digital maps. Street view is the most common scene during driving. Since streets are often full of shops with signboards, scene text recognition over the shop sign images in street views is of great significance and utility to urban scene understanding in ITS. To advance research in this field, (1) we build ShopSign , which is a large-scale scene text dataset of Chinese shop signs in street views. It contains 25,770 natural scene images, and 267,049 text instances. The images in ShopSign were captured in different scenes, from downtown to developing regions, and across 8 provinces and 20 cities in China, using more than 50 different mobile phones. It is very sparse and imbalanced in nature. (2) we carry out a comprehensive empirical study on the performance of state-of-the-art DL based scene text reading algorithms on ShopSign and three other Chinese scene text datasets, which has not been addressed in the literature before. Through comparative analysis, we demonstrate that language has a critical influence on scene text detection. Moreover, by comparing the accuracy of four scene text recognition algorithms, we show that there is a very large room for further improvements in street view text recognition to fit real-world ITS applications.

With the proposal and development of Generative Adversarial Networks, the great achievements in the field of image generation are made. Meanwhile, many works related to the generation of painting art have also been derived. However, due to the difficulty of data collection and the fundamental challenge from freehand expressions, the generation of traditional Chinese painting is still far from being perfect. This paper specialises in Chinese art painting generation of flowers, which is important and classic, by deep learning method. First, an unpaired flowers paintings data set containing three classic Chinese painting style: line drawing, meticulous, and ink is constructed. Then, based on the collected dataset, a Flower‐Generative Adversarial Network framework to generate multi‐style Chinese art painting of flowers is proposed. The Flower‐Generative Adversarial Network, consisting of attention‐guided generators and discriminators, transfers the style among line drawing, meticulous, and ink by an adversarial training way. Moreover, in order to solve the problem of artefact and blur in image generation by existing methods, a new loss function called Multi‐Scale Structural Similarity to force the structure preservation is introduced. Extensive experiments show that the proposed Flower‐Generative Adversarial Network framework can produce better and multi‐style Chinese art painting of flowers than existing methods.

Multiple morphological abnormalities of the sperm flagella (MMAF) is a severe form of asthenoteratozoospermia. Although recent studies have revealed several MMAF-associated genes and demonstrated MMAF to be a genetically heterogeneous disease, at least one-third of the cases are still not well understood for their etiology. Here, we identified bi-allelic loss-of-function variants in CFAP58 by using whole-exome sequencing in five (5.6%) unrelated individuals from a cohort of 90 MMAF-affected Chinese men. Each of the men harboring bi-allelic CFAP58 variants presented typical MMAF phenotypes. Transmission electron microscopy demonstrated striking flagellar defects with axonemal and mitochondrial sheath malformations. CFAP58 is predominantly expressed in the testis and encodes a cilia- and flagella-associated protein. Immunofluorescence assays showed that CFAP58 localized at the entire flagella of control sperm and predominantly concentrated in the mid-piece. Immunoblotting and immunofluorescence assays showed that the abundances of axoneme ultrastructure markers SPAG6 and SPEF2 and a mitochondrial sheath protein, HSP60, were significantly reduced in the spermatozoa from men harboring bi-allelic CFAP58 variants. We generated Cfap58-knockout mice via CRISPR/Cas9 technology. The male mice were infertile and presented with severe flagellar defects, consistent with the sperm phenotypes in MMAF-affected men. Overall, our findings in humans and mice strongly suggest that CFAP58 plays a vital role in sperm flagellogenesis and demonstrate that bi-allelic loss-of-function variants in CFAP58 can cause axoneme and peri-axoneme malformations leading to male infertility. This study provides crucial insights for understanding and counseling of MMAF-associated asthenoteratozoospermia.

Stimulated Raman scattering (SRS) microscopy is an emerging technology that provides high chemical specificity for endogenous biomolecules and can circumvent common constraints of fluorescence microscopy including limited capabilities to probe small biomolecules and difficulty resolving many colors simultaneously due to spectral overlap. However, the resolution of SRS microscopy remains governed by the diffraction limit. To overcome this, we describe a new technique called Molecule Anchorable Gel-enabled Nanoscale Imaging of Fluorescence and stImulatEd Raman Scattering microscopy (MAGNIFIERS), that integrates SRS microscopy with expansion microscopy (ExM). ExM is a powerful strategy providing significant improvement in imaging resolution by physical magnification of hydrogel-embedded preserved biological specimens. MAGNIFIERS offers chemical-specific nanoscale imaging with sub-50 nm resolution and has scalable multiplexity when combined with multiplex Raman probes and fluorescent labels. We used MAGNIFIERS to visualize nanoscale features in a label-free manner with C-H vibration of proteins, lipids and DNA in a broad range of biological specimens, from mouse brain, liver and kidney to human lung organoid. In addition, we applied MAGNIFIERS to track nanoscale features of protein synthesis in protein aggregates using metabolic labeling of small metabolites. Finally, we used MAGNIFIERS to demonstrate 8-color nanoscale imaging in an expanded mouse brain section. Overall, MAGNIFIERS is a valuable platform for super-resolution label-free chemical imaging, high-resolution metabolic imaging, and highly multiplexed nanoscale imaging, thus bringing SRS to nanoscopy.

Background Potassium channels are important for the structure and function of the spermatozoa. As a potassium transporter, the mSlo3 is essential for male fertility as Slo3 knockout male mice were infertile with the series of functional defects in sperm cells. However, no pathogenic variant has been detected in human SLO3 to date. Here we reported a human case with homozygous SLO3 mutation. The function of SLO3 in human sperm and the corresponding assisted reproductive strategy are also investigated. Methods We performed whole-exome sequencing analysis from a large cohort of 105 patients with asthenoteratozoospermia. The effects of the variant were investigated by quantitative RT-PCR, western blotting, and immunofluorescence assays using the patient spermatozoa. Sperm morphological and ultrastructural studies were conducted using haematoxylin and eosin staining, scanning and transmission electron microscopy. Results We identified a homozygous missense variant (c.1237A > T: p.Ile413Phe) in the sperm-specific SLO3 in one Chinese patient with male infertility. This SLO3 variant was rare in human control populations and predicted to be deleterious by multiple bioinformatic tools. Sperm from the individual harbouring the homozygous SLO3 variant exhibited severe morphological abnormalities, such as acrosome hypoplasia, disruption of the mitochondrial sheath, coiled tails, and motility defects. The levels of SLO3 mRNA and protein in spermatozoa from the affected individual were reduced. Furthermore, the acrosome reaction, mitochondrial membrane potential, and membrane potential during capacitation were also afflicted. The levels of acrosome marker glycoproteins and PLCζ1 as well as the mitochondrial sheath protein HSP60 and SLO3 auxiliary subunit LRRC52, were significantly reduced in the spermatozoa from the affected individual. The affected man was sterile due to acrosome and mitochondrial dysfunction; however, intra-cytoplasmic sperm injection successfully rescued this infertile condition. Conclusions SLO3 deficiency seriously impact acrosome formation, mitochondrial sheath assembly, and the function of K+ channels. Our findings provided clinical implications for the genetic and reproductive counselling of affected families.

The energy efficiency enhancement induced by RD the energy intensity will decrease by 78.4% in 2030 compared to that in 2005. The energy consumption and carbon emissions will be significantly lower than that in the baseline scenario, and will peak at 2672Mtce and 6042 Mt respectively in 2021. Moreover, the paths of energy efficiency enhancement induced by R&D investment in various industrial sub-sectors are worth studying in the further work.

Summary The reactions catalyzed by the delta-5 and delta-6 desaturases (D5D/D6D), key enzymes responsible for highly unsaturated fatty acid (HUFA) synthesis, regenerate NAD+ from NADH. Here, we show that D5D/D6D provide a mechanism for glycolytic NAD+ recycling that permits ongoing glycolysis and cell viability when the cytosolic NAD+/NADH ratio is reduced, analogous to lactate fermentation. Although lesser in magnitude than lactate production, this desaturase-mediated NAD+ recycling is acutely adaptive when aerobic respiration is impaired in vivo. Notably, inhibition of either HUFA synthesis or lactate fermentation increases the other, underscoring their interdependence. Consistent with this, a type 2 diabetes risk haplotype in SLC16A11 that reduces pyruvate transport (thus limiting lactate production) increases D5D/D6D activity in vitro and in humans, demonstrating a chronic effect of desaturase-mediated NAD+ recycling. These findings highlight key biologic roles for D5D/D6D activity independent of their HUFA end products and expand the current paradigm of glycolytic NAD+ regeneration.

This study focus on the economy of the solar thermal and air source heat pump combined system supplying the same demand of SH and DHW for a city household at different locations in China, namely; Beijing, Xi’an and Nanjing. These three locations represent the climatic conditions variety in China with different outdoor temperatures and solar radiation. At each location, the optimized simulations are carried out to recognize the most economical configurations. The results show that, for a 15-year running time, the system comprising 10m2 solar collectors and 5 kW air source heat pump is the best configuration having the minimum cost for all three cities, but the minimum cost of which is different for each location. At Nanjing, the system has the lowest cost of all the three cities, and the payback time of which is also the shortest. However, the payback time of the optimum system in Beijing is 15.9 years exceeding its running time, due to the lowest central heating fee included in the cost of the traditional heating method.

The necessity and rationality of college student evaluation are elaborated through analyzing the evaluation grades of a school of University of Jinan, and the caused problems and malpractices are pointed out. We think that student evaluation basically reflects the teaching level of teachers, at least the ranking of their teaching ability, and is deserved to be extended.

Dense phase pneumatic conveying of pulverized fuel particles under high pressure is one of the key techniques in large scale gasification of coal and petroleum coke. The real time and continuous measurement of dense phase gas–solid flow parameters such as particle velocity, concentration and mass flow rate has great significance for the in-depth understanding of particle flow dynamic behaviors and the optimized design of the conveying system. In this paper, an integrated electrostatic sensor is designed and used to explore the flow characteristics of anthracite and petroleum coke particles on a dense phase pneumatic conveyor. The ring electrodes in the integrated sensor are capable of measuring the “mean” velocity of solid particles over the whole cross-section of the pipeline, while the arc electrodes are employed to determine the local velocity of particles near them. The experimental results on a dense phase pneumatic conveyor under high pressure demonstrate that the flow characteristics depend on the physical properties of solid particles and carrying gas. Petroleum coke particles are much easier to be suspended in the gas flow than the anthracite particles, but its flow stability is worse. The local velocities from the arc electrode pairs mounted on the top of the pipeline are usually higher than those from the arc electrodes on the bottom for a stratified flow. The velocity from the ring electrode pair, indicating the mean velocity of particles over the whole cross-section, is usually higher than the local velocities from the arc electrode pairs for a suspension flow. In addition, the relationship between the mass flow rate and charge level of dense phase pneumatically conveyed solid particles is very complicated due to the complexity of the particle flow and the charge level cannot be used to measure particle concentration or mass flow rate.

Lean principles provide improvement to the efficiency of construction by synchronizing the process of building and eliminating waste, which in turn can have a positive impact on the environment. This is generating a growing interest in linking the relationship between lean and low carbon. The authors compare the carbon emission in the truss construction process of a steel structured building in China optimized by lean principles with the original process. A partial life cycle assessment (LCA) framework is used to calculate the embodied carbon of materials, energy consumption of transportation from cradle to site, energy consumption of construction equipment and disposal of construction waste. This confirms through case study and measurement what had previously been proposed and adds the aspect of site efficiency into the current method for life cycle assessment of carbon emission. The results show that the lean process had an embodied carbon of 5532.1t CO2e delivering a reduction of 43t compared to the original process, demonstrating lean interventions can have a positive impact on the environment. This study establishes the link between the efficiency of the construction process and low carbon using empirical evidence demonstrating that contractors can use lean principles in their construction processes to improve efficiency and reduce carbon emissions as a result.

Life cycle thinking has become widely applied in the assessment for building environmental performance. Various tool are developed to support the application of life cycle assessment (LCA) method. This paper focuses on the carbon emission during the building construction stage. A partial LCA framework is established to assess the carbon emission in this phase. Furthermore, five typical LCA tools programs have been compared and analyzed for demonstrating the current application of LCA tools and their limitations in the building construction stage. Based on the analysis of existing tools and sustainability demands in building, a new computer calculation system has been developed to calculate the carbon emission for optimizing the sustainability during the construction stage. The system structure and detail functions are described in this paper. Finally, a case study is analyzed to demonstrate the designed LCA framework and system functions. This case is based on a typical building in UK with different plans of masonry wall and timber frame to make a comparison. The final results disclose that a timber frame wall has less embodied carbon emission than a similar masonry structure. 16% reduction was found in this study.

This study focuses on the economy of two renewable systems supplying the same demand of domestic hot water (DHW) and space heating (SH) for a city household located in Beijing of China. The systems are the solar thermal system and air source heat pump system. Both the two systems are considered for meeting the energy demand of SH and DHW. Optimized simulations are carried out to recognize the most economical configurations. The results show that, for a 15-year running time, the air source heat pump system comprising a 10 kW air source heat pump is the best configuration and has the minimum cost.

The complete genome of the solvent tolerant Staphylococcus warneri SG1 was recently published. This Gram-positive bacterium is tolerant to a large spectrum of organic solvents including short-chain alcohols, alkanes, esters and cyclic aromatic compounds. In this study, we applied a two-dimensional liquid chromatography (2D-LC) mass spectrometry (MS) shotgun approach, in combination with quantitative 2-MEGA (dimethylation after guanidination) isotopic labeling, to compare the proteomes of SG1 grown under butanol-free and butanol-challenged conditions. In total, 1585 unique proteins (representing 65% of the predicted open reading frames) were identified, covering all major metabolic pathways. Of the 967 quantifiable proteins by 2-MEGA labeling, 260 were differentially expressed by at least 1.5-fold. These proteins are involved in energy metabolism, oxidative stress response, lipid and cell envelope biogenesis, or have chaperone functions. We also applied differential isotope labeling LC-MS to probe metabolite changes in key metabolic pathways upon butanol stress. This is the first comprehensive proteomic and metabolomic study of S. warneri SG1 and presents an important step toward understanding its physiology and mechanism of solvent tolerance.

The feasibility of characterization of human blood fibrinogen levels using optical coherence tomography (OCT) was investigated. Three groups of blood samples were reconstituted of red blood cells: 1) phosphate-buffered saline; 2) plasma with its intrinsic fibrinogen removed and commercial fibrinogen added; and 3) native plasma with various fibrinogen levels (0–12 g/L). OCT signal slope (OCTSS) of blood was extracted from OCT depth-reflectivity profiles. Effects of hematocrit (HCT) and blood flow on OCTSS of the blood under various fibrinogen concentrations were also studied. The results of blood flowing at 5 mm/s showed that OCTSS of all the three groups at HCT of 40% decreases with the increasing fibrinogen concentration up to a certain level, i. e., >8, 6, and 4 g/L for groups 1, 2, and 3, respectively. The blood of group 2 at HCTs of 30%, 40%, and 50% had a rapid decrease in OCTSS in the range of fibrinogen concentration of 0–2, 0–6, and 0–10 g/L, respectively. OCTSS value of blood flowing at 2.5 mm/s was lower than that at 5 mm/s at each fibrinogen concentration. In conclusion, OCTSS has a strong correlation with plasma fibrinogen concentration, and has the potential to identify the abnormal level of human blood fibrinogen.

A multimodal tomography system based on the electrical capacitance and electrostatic sensor arrays is proposed to investigate the effects of particle charging in the pipe on electrical capacitance tomography (ECT). The effect of the charge in the pipe on the detection circuit of ECT is firstly analyzed. Then the simulations are performed to make further investigation on the effect of the charge distribution on ECT. The simulation results indicate that the electrostatic effects on ECT vary with the spatial distribution of the charge in the pipe. The charges near the pipe wall have greater effect on ECT than those in the center of the pipe. The capacitance electrode-pairs near the charge distribution are greatly affected. Experiments are also performed on a pulley rig, which verify the simulation results.

A method for gas&ndash, solid two-phase flow pattern identification in horizontal pneumatic conveying pipelines is proposed based on an electrostatic sensor array (ESA) and artificial neural network (ANN). The ESA contains eight identical arc shaped electrodes. Numerical simulation is conducted to discuss the contributions of the electrostatic signals to the flow patterns according to the error recognition rate, and the results show that the amplitudes of the output signals from each electrode of the ESA can give important information on the particle distribution and further infer the flow patterns. In experiments, the average values and standard deviations of the eight output signals&rsquo, amplitudes are respectively extracted as the inputs of the ANN to identify four kinds of flow patterns in a pneumatic conveying pipeline, which are fully suspended flow, stratified flow, dune flow and slug flow. Results show that for any one of those two input values, the correct rates of the ANN model are all 100%.

In recent years, great advance has been made on electrostatic sensing technique for gas-solid flow measurement. Electrostatic tomography(EST) has been used in experiment researches as a novel non-intrusive measurement technique. Electrostatic sensor array is one of the key parts of electrostatic tomography system. Based on the image reconstruction algorithm, the charge on the particles can be obtained from the electrostatic measurement signals. However, reports on the relationship between the electrostatic signal acquired by the electrostatic sensor array and flow characteristics of the particles were very few. In this paper the mathematical model of the electrostatic sensor array was adopted, and its spatial sensitivity field was investigated. In the experiment, the electrostatic signals of the quarter flow and full pipe flow were acquired by the electrostatic sensor array. Based on the EST experiment and Power Spectrum Analysis of Signal, the energy distributions of those two flow patterns were compared. Results show that the sensitivity of the electrostatic sensor array is inhomogeneous in three-dimensional space. For this reason, the energy distributions of those two flow patterns are distinguished.

Particle is charged due to frictional contact and collisions between particles and pipe wall. Electrostatic tomography technology (EST) is used to monitor the traveling particle charge. However the electric field distribution in the electrostatic sensor arrays is simultaneously affected by both the particle permittivity distribution and particle charge. In the paper, the effect of the different particle flow regimes on EST is investigated numerically and experimentally. Results indicated the particle distribution affected the induced charge on the electrostatic sensor array. But the effect relates to the relationship between the charge distribution and the particle distribution. Furthermore, a fusion of dual modality tomography system consisting of a capacitance sensor and electrostatic sensor arrays is used to investigate the relationship between the particle distribution and charge distribution in a gravity conveying rig. Results showed that the higher particle concentration has higher charge distribution in the gravity conveying rig. Additionally, the measurement of the mass flow rate by EST was investigated.

Optical coherence tomography (OCT) has been used to evaluate blood coagulation process and is proved efficiently by using OCT signal slope and 1/e light penetration depth (D 1/e ). The purpose of this study is to investigate the effect of pH on the two optical properties of whole blood during in vitro clot formation under static by optical coherence tomography. After the addition of 0.9% (w/v) sodium chloride solution with pH=6, 7, 8, 9, OCT signal slope (OCTSS) have a total decrease of 6.98%, 4.07%, 4.16%, 3.69% after 60-min coagulation, and the blood clotting time are 985, 1041, 1065, 967, respectively. Our results suggest that when blood pH was lower or higher than normal value, the blood clotting time shows a decrease and the process of blood coagulation appears abnormal.

This study compared the hepatic glucuronidation of Picroside II in different species and characterized the glucuronidation activities of human intestinal microsomes (HIMs) and recombinant human UDP-glucuronosyltransferases (UGTs) for Picroside II. The rank order of hepatic microsomal glucuronidation activity of Picroside II was ratmousehumandog. The intrinsic clearance of Picroside II hepatic glucuronidation in rat, mouse and dog was about 10.6-, 6.0- and 2.3-fold of that in human, respectively. Among the 12 recombinant human UGTs, UGT1A7, UGT1A8, UGT1A9 and UGT1A10 catalyzed the glucuronidation. UGT1A10, which are expressed in extrahepatic tissues, showed the highest activity of Picroside II glucuronidation (K(m) = 45.1 μM, V(max) = 831.9 pmol/min/mg protein). UGT1A9 played a primary role in glucuronidation in human liver microsomes (HLM; K(m) = 81.3 μM, V(max) = 242.2 pmol/min/mg protein). In addition, both mycophenolic acid (substrate of UGT1A9) and emodin (substrate of UGT1A8 and UGT1A10) could inhibit the glucuronidation of Picroside II with the half maximal inhibitory concentration (IC(50)) values of 173.6 and 76.2 μM, respectively. Enzyme kinetics was also performed in HIMs. The K(m) value of Picroside II glucuronidation was close to that in recombinant human UGT1A10 (K(m) = 58.6 μM, V(max) = 721.4 pmol/min/mg protein). The intrinsic clearance was 5.4-fold of HLMs. Intestinal UGT enzymes play an important role in Picroside II glucuronidation in human.

Glycyrrhetinic acid, the active metabolite of glycyrrhizin, is primarily eliminated by glucuronidation reaction in vivo. In spite of the widespread clinical use of glycyrrhizin, UDP-glucuronosyltransferase (UGT) isoforms involved in the glucuronidation of this drug are still unknown. This report identifies and characterizes the UGT isoforms responsible for glycyrrhetinic acid glucuronidation. In the enzymatic kinetic experiment performed with pooled human liver microsomes (HLMs), K(m) was 39.4 microM and V(max) was 609.2 pmol/min/mg protein. Of the baculosomes expressing 12 recombinant UGTs investigated, UGT1A1, 1A3, 2B4 and 2B7 showed catalytic activity and UGT1A3 exhibited the highest activity. K(m) values of recombinant UGT1A3 and 2B7 were 3.4 and 4.4 microM, respectively. Both imipramine (typical substrate of UGT1A3 and 1A4) and flurbiprofen (typical substrate of UGT2B7) inhibit the glucuronidation of glycyrrhetinic acid. Estimated IC(50) values were 138 microM for flurbiprofen and 207 microM for imipramine in the inhibition of the glucuronidation of glycyrrhetinic acid in HLMs. These results suggest that glycyrrhetinic acid glucuronidation is primarily mediated by UGT1A1, 1A3, 2B4 and 2B7.

Experiments are performed in a dense-phase pneumatic conveying system of pulverized coal, and electrostatic signals and coal particle distribution images over cross-section of the pipeline at superficial gas velocities of 5.7 m/s, 6.9 m/s, and 8.1 m/s are obtained through use of electrostatic sensor arrays (ESA) and electrical capacitance tomography (ECT), respectively. In combination with ECT imaging results, the output signals of the ESA are analyzed by FFT and approximate entropy method. Results show that characteristic of particles motion and its change with increasing superficial gas velocity are different in the dense and dilute phase region of the pipe. With increasing the superficial gas velocity, the peak frequency of the electrostatic signal increases linearly in dense-phase region, while that in dilute phase region is nonlinear, implying that the increase of the axial particles velocity is the main dynamic change, while in dilute phase regions, the particles velocity fluctuation in the radial direction cannot be ignored. The ApEn value of the electrostatic signal in dense phase region is larger than that in dilute phase region. When the ApEn value difference of the electrostatic signals is smaller, the pulverized coal particles are better suspended.

This study investigates the optical properties of human blood during the coagulation process under statics using optical coherence tomography (OCT). OCT signal slope (OCTSS) and 1/e light penetration depth (d1/e) were obtained from the profiles of reflectance versus depth. Results showed that both OCTSS and d1/e were able to sensitively differentiate various stages of blood properties during coagulating. After 1 h clotting, OCTSS decreased by 47.0%, 15.0%, 13.7%, and 8.5% and d1/e increased by 34.7%, 29.4%, 24.3%, and 22.9% for the blood samples at HCT of 25%, 35%, 45%, and 55%, respectively. The slope of d1/e versus time (Sr, ×10 −4 mm/s), associated with clot formation rate decreased from 6.0 ±0.3, 3.7 ± 0.5 to 2.3±0.4 with the increasing of HCT from 35%, 45%, to 55%. The clotting time (tc )f rom thed1/e evolution curves was estimated to be 1969 ±92 s, 375 ±12 s, 455 ±11 s, and 865 ±47 s for the blood of 25%, 35%, 45%, and 55%. This study demonstrates that the parameters (tc and Sr) from the variations in d1/e had better sensitivity and smaller standard deviation. Furthermore, blood hematocrit affecting backscattering properties of blood during coagulation was capable of being discerned by OCT parameters. It is concluded that OCT is a potential technique to quantify and follow the liquid-gel transition of blood during clotting. C 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). (DOI: 10.1117/1.3615667)