USE OF OSMOTIC TENSIOMETERS IN THE DETERMINATION OF SOIL-WATER CHARACTERISTIC CURVES

Soil-water characteristic curve (SWCC) correlates the water content of a soil to its soil suction, which is a very important property of unsaturated soils. Osmotic tensiometers (OTs) have shown their capability in high soil suction measurement. This study tried to use OT combined with a pressure plate and WP4C dewpoint potentiometer to determine the SWCC of a residual soil. Three OTs with different measuring ranges (900 kPa, 1200 kPa, 2300 kPa) were prepared for soil suction measurement. The temperature effect on the pressure variations of OTs was illustrated based on Flory-Huggins polymer theories and an appropriate calibration equation was proposed to eliminate the temperature effect on the accuracy of soil suction measurement using OT. The OT showed a fast response in soil suction measurement and the equilibrium can be established in 10–15 min during SWCC measurement. Comparison of the SWCC data obtained from the pressure plate, OT, and WP4C dewpoint potentiometer proves that the OT had good performance in the determination of SWCC, especially for the transition zone (i.e., 10–1500 kPa suction range), by providing more data points to define the SWCC in a shorter period. The results show that the usage of OT will shorten the time required for the determination of SWCC and could be considered as a new and reliable technique in SWCC measurement

Female-biased expression of long non-coding RNAs in domains that escape X-inactivation in mouse

<p>Abstract</p> <p>Background</p> <p>Sexual dimorphism in brain gene expression has been recognized in several animal species. However, the relevant regulatory mechanisms remain poorly understood. To investigate whether sex-biased gene expression in mammalian brain is globally regulated or locally regulated in diverse brain structures, and to study the genomic organisation of brain-expressed sex-biased genes, we performed a large scale gene expression analysis of distinct brain regions in adult male and female mice.</p> <p>Results</p> <p>This study revealed spatial specificity in sex-biased transcription in the mouse brain, and identified 173 sex-biased genes in the striatum; 19 in the neocortex; 12 in the hippocampus and 31 in the eye. Genes located on sex chromosomes were consistently over-represented in all brain regions. Analysis on a subset of genes with sex-bias in more than one tissue revealed Y-encoded male-biased transcripts and X-encoded female-biased transcripts known to escape X-inactivation. In addition, we identified novel coding and non-coding X-linked genes with female-biased expression in multiple tissues. Interestingly, the chromosomal positions of all of the female-biased non-coding genes are in close proximity to protein-coding genes that escape X-inactivation. This defines X-chromosome domains each of which contains a coding and a non-coding female-biased gene. Lack of repressive chromatin marks in non-coding transcribed loci supports the possibility that they escape X-inactivation. Moreover, RNA-DNA combined FISH experiments confirmed the biallelic expression of one such novel domain.</p> <p>Conclusion</p> <p>This study demonstrated that the amount of genes with sex-biased expression varies between individual brain regions in mouse. The sex-biased genes identified are localized on many chromosomes. At the same time, sexually dimorphic gene expression that is common to several parts of the brain is mostly restricted to the sex chromosomes. Moreover, the study uncovered multiple female-biased non-coding genes that are non-randomly co-localized on the X-chromosome with protein-coding genes that escape X-inactivation. This raises the possibility that expression of long non-coding RNAs may play a role in modulating gene expression in domains that escape X-inactivation in mouse.</p

Upregulated integrin α11 in the stroma of cutaneous squamous cell carcinoma promotes skin carcinogenesis

Integrin α11β1 is a collagen-binding integrin that is needed to induce and maintain the myofibroblast phenotype in fibrotic tissues and during wound healing. The expression of the α11 is upregulated in cancer-associated fibroblasts (CAFs) in various human neoplasms. We investigated α11 expression in human cutaneous squamous cell carcinoma (cSCC) and in benign and premalignant human skin lesions and monitored its effects on cSCC development by subjecting α11-knockout (Itga11−/−) mice to the DMBA/TPA skin carcinogenesis protocol. α11-deficient mice showed significantly decreased tumor cell proliferation, leading to delayed tumor development and reduced tumor burden. Integrin α11 expression was significantly upregulated in the desmoplastic tumor stroma of human and mouse cSCCs, and the highest α11 expression was detected in high-grade tumors. Our results point to a reduced ability of α11-deficient stromal cells to differentiate into matrix-producing and tumor-promoting CAFs and suggest that this is one causative mechanism underlying the observed decreased tumor growth. An unexpected finding in our study was that, despite reduced CAF activation, the α11-deficient skin tumors were characterized by the presence of thick and regularly aligned collagen bundles. This finding was attributed to a higher expression of TGFβ1 and collagen crosslinking lysyl oxidases in the Itga11-/- tumor stroma. In summary, our data suggest that α11β1 operates in a complex interactive tumor environment to regulate ECM synthesis and collagen organization and thus foster cSCC growth. Further studies with advanced experimental models are still needed to define the exact roles and molecular mechanisms of stromal α11β1 in skin tumorigenesis.publishedVersio

Development of new osmotic tensiometers for high soil suction measurement

Soil can be divided into unsaturated soil and saturated soil according to the position of the groundwater table. The soil above the groundwater table is defined as unsaturated soil and it has four components including air, water, air-water interface, and solid soil particles. In unsaturated soil, its soil suction can significantly influence the hydromechanical behavior and engineering properties of the soil. Soil suction comprises two parts: matric suction and osmotic suction. Matric suction is caused by the capillarity of soil particles on pore-water and its value is defined as the difference between the pore-air pressure and the pore-water pressure, while osmotic suction relates to the dissolved salts in the pore-water of the soil. Conventional water-filled tensiometers are widely used for direct measurement of matric suction under atmospheric conditions. The conventional tensiometer usually consists of a ceramic disk, a chamber filled with water, and a pressure transducer. The measuring range of the conventional tensiometer is up to 90 kPa due to the cavitation problem. Compared with conventional tensiometers, polymer-filled osmotic tensiometers (OTs) can measure a higher matric suction by increasing the osmotic pressure of the water inside the tensiometer. Similar to the suction measurement process using the conventional tensiometer, when placing the OT in contact with the soil for soil suction measurement, the suction of the soil will induce a drop in the osmotic pressure of the water in the polymer chamber of the OT and this drop is the value of matric suction of the soil. The measuring range of an OT is equal to the maximum water pressure of the OT during pressure observation. However, the long-term water pressure decay of OT caused a gradual decrease in its measuring range. All previous research used commercial polymers in developing OT and the mechanism of water pressure decay of OT was not found. In this research, the mechanism of water pressure decay in OT was first studied by correlating to polymer theories and appropriate super-water absorbent polymers were synthesized to develop new OTs with a constant measuring range. The good performance of the developed OTs in soil suction measurement was evaluated using the undisturbed residual soil specimens. The temperature effect on OT was also studied based on polymer theories. Commercial crosslinked poly(acrylamide-co-acrylic acid) potassium salt (PAM-co-PAAK) was used for the preparation of OTs to explore the mechanism of water pressure decay of OTs. The maximum water pressure in the OT (i.e., the measuring range of the OT) versus the volume fraction of polymer filled in the OT was described based on the Flory-Huggins polymer theories and validated using the WP4C dewpoint potentiometer. The long-term observation of pressure variation of OTs indicates that the pressure decay of OT was mainly caused by the stress relaxation of the polymer hydrogels, and the standard linear solid (SLS) rheological model can fit the decay data properly. The ultraviolet-visible spectrophotometry demonstrated that there was no increase in polymer leakage during the period of pressure decay of OTs. As a result, the pressure decay of OT was proved not caused by polymer leakage. Referring to the mechanism of water pressure decay in OT, new OTs were developed using synthesized polymers. Polymers including polyacrylamide (PAM) and sodium polyacrylate (NaPA) with different degrees of cross-linking were synthesized by UV polymerization. Long-term pressure variations of OTs show that PAM-filled OTs have a faster stress relaxation behavior than NaPA-filled OTs and thus can keep constant pressure (i.e. constant measuring range) for a long time. However, the measuring range of PAM-filled OTs is lower than that of NaPA-filled OTs when the same mass of polymer was filled in OT. The residual soil specimens with controlled matric suction were used to evaluate the performance of OTs in matric suction measurement. The results demonstrated that OTs can measure matric suction with fast response and high accuracy. Three OTs with different measuring ranges were prepared to study the temperature effect on the pressure variation of OT. The pressure decay of OT was proved insignificant to the accuracy of soil suction measurement if the measurement can be conducted in a short time (e.g., less than one hour). Based on Flory-Huggins polymer theories, an appropriate temperature calibration equation was proposed to eliminate the temperature effect on soil suction measurement using OT. The developed OT was also used to determine the SWCC of a residual soil over the full range by combining it with a pressure plate and WP4C dewpoint potentiometer. Comparison of the experimental data from the pressure plate, OT, and WP4C dewpoint potentiometer proves that the OT had good performance in the determination of SWCC, especially for the transition zone (i.e., 10 – 1500 kPa suction range), by providing more data points to define the SWCC in a shorter period. The usage of OT will improve the accuracy and the speed of high soil suction measurement, thus shortening the time required for the determination of SWCC. The results of this research show that the developed OT could be considered as a new and reliable instrument in high matric suction measurement and thus contribute to the research and application of unsaturated soil mechanics.Doctor of Philosoph

Design of battery-free real-time pulse detection system based on near field communication

With great flexibility, high sensitivity, and low power consumption properties, wearable sensors can be widely used in many aspects, such as intelligent robots, human physiological signal detections, etc. Apart from fabrication and performance testing of wearable sensors, building efficient and reliable electronic system for sensors to broaden their application areas is also very important. With characteristics of extremely low power consumption, simple energy harvesting process and quickly contactless data acquisition, near-field communication (NFC) technology can be applied with specific wearable sensors to create miniaturized battery-free wireless devices and systems for signal detection and sample collection. This dissertation focuses on the application of a new type wearable pressure sensor in human healthcare and designs the related wearable devices based on NFC technology to detect the variation of human pulse. Firstly, previous work related to the design and application of wearable devices in human health monitoring and detection will be reviewed. Secondly, some critical design methods and procedures of the human pulse detection system will be described and shown thoroughly, including the fabrication of wearable pressure sensors, the layout of functional components in the detection system based on NFC technology, the pulse data acquisition and display facilitated by a demo app written by using Android Studio. According to the finished real-time pulse detection system, data acquisition process can be displayed by means of plotting in the NFC-enabled smartphone. Finally, the detected pulse information will be analyzed and some conclusions related to the detection system will be drawn. Future work of the detection system will be given in the end.Master of Science (Smart Product Design

Use of synthesised polymers for the development of new osmotic tensiometers

Compared with conventional water-filled tensiometers, polymer-filled osmotic tensiometers (OTs) can measure a higher matric suction by increasing the osmotic pressure of the water inside the tensiometer. The measuring range of OT is equal to the osmotic pressure of water inside the OT. All previous research used commercial polymers in developing OTs and the mechanism of long-term pressure decay of OTs was not found. In this study, polymers including polyacrylamide (PAM) and sodium polyacrylate (NaPA) with different degrees of crosslinking were synthesised by UV polymerisation to develop new OTs. Long-term pressure variations of OTs indicated that the pressure decay was more likely due to the stress relaxation of polymer materials instead of polymer leakage. PAM-filled OTs have a faster stress relaxation behaviour than NaPA-filled OTs so that they can keep constant pressure (i.e., constant measuring range) for a long time and there is no need for pressure correction based on the pressure decay rate. However, the measuring range of PAM-filled OTs is lower than that of NaPA-filled OTs. The result of matric suction measurements demonstrated that the proposed OTs can be used to measure matric suction both in low and high ranges with fast response and high accuracy.Nanyang Technological UniversityNational Parks BoardSubmitted/Accepted versionThe authors would like to acknowledge the financial support from Nanyang Environment and Water Research Institute (NEWRI), Interdisciplinary Graduate School, Nanyang Technological University, Singapore, as well as the National Parks Board, Singapore

Developing luminescent ratiometric thermometers based on a Covalent Organic Framework (COF)

Covalent Organic Frameworks (COFs), an emerging class of crystalline porous materials, are proposed as a new type of support for grafting lanthanide ions (Ln(3+)) and employing these hybrid materials as ratiometric luminescent thermometers. ATpBpy-COF-prepared from 1,3,5-triformyl-phloroglucinol (Tp) and 2,2'-bipyridine-5,5'-diamine (Bpy) grafted with Eu/Tb and Dy acetylacetone (acac) complexes can be successfully used as a luminescent thermometer in the 10-360 K (Eu) and 280-440 K (Tb) ranges with good sensing properties (thermal sensitivity up to 1.403% K-1, temperature uncertainty delta T < 1 K above 110 K). For the Eu/Tb systems, we observe an unusual and rarely reported behavior, that is, no thermal quenching of the Tb3+ emission, a result of the absence of ion-to-ligand/host energy back-transfer. The LnCOF materials proposed here could be a new class of materials employed for temperature-sensing applications following up on the well-known luminescent metal-organic framework thermometers

Genome-Wide Identification of MADS-Box Family Genes in Safflower (<i>Carthamus tinctorius</i> L.) and Functional Analysis of <i>CtMADS24</i> during Flowering

Safflower is an important economic crop with a plethora of industrial and medicinal applications around the world. The bioactive components of safflower petals are known to have pharmacological activity that promotes blood circulation and reduces blood stasis. However, fine-tuning the genetic mechanism of flower development in safflower is still required. In this study, we report the genome-wide identification of MADS-box transcription factors in safflower and the functional characterization of a putative CtMADS24 during vegetative and reproductive growth. In total, 77 members of MADS-box-encoding genes were identified from the safflower genome. The phylogenetic analysis divided CtMADS genes into two types and 15 subfamilies. Similarly, bioinformatic analysis, such as of conserved protein motifs, gene structures, and cis-regulatory elements, also revealed structural conservation of MADS-box genes in safflower. Furthermore, the differential expression pattern of CtMADS genes by RNA-seq data indicated that type II genes might play important regulatory roles in floral development. Similarly, the qRT-PCR analysis also revealed the transcript abundance of 12 CtMADS genes exhibiting tissue-specific expression in different flower organs. The nucleus-localized CtMADS24 of the AP1 subfamily was validated by transient transformation in tobacco using GFP translational fusion. Moreover, CtMADS24-overexpressed transgenic Arabidopsis exhibited early flowering and an abnormal phenotype, suggesting that CtMADS24 mediated the expression of genes involved in floral organ development. Taken together, these findings provide valuable information on the regulatory role of CtMADS24 during flower development in safflower and for the selection of important genes for future molecular breeding programs

α11β1 integrin is induced in a subset of cancer- associated fibroblasts in desmoplastic tumor stroma and mediates in vitro cell migration

Integrin α11β1 is a collagen receptor that has been reported to be overexpressed in the stroma of non-small cell lung cancer (NSCLC) and of head and neck squamous cell carcinoma (HNSCC). In the current study, we further analyzed integrin α11 expression in 14 tumor types by screening a tumor tissue array while using mAb 203E3, a newly developed monoclonal antibody to human α11. Different degrees of expression of integrin α11 were observed in the stroma of breast, ovary, skin, lung, uterus, stomach, and pancreatic ductal adenocarcinoma (PDAC) tumors. Co-expression queries with the myofibroblastic cancer-associated fibroblast (myCAF) marker, alpha smooth muscle actin (αSMA), demonstrated a moderate level of α11+ in myCAFs associated with PDAC and HNSCC tumors, and a lack of α11 expression in additional stromal cells (i.e., cells positive for fibroblast-specific protein 1 (FSP1) and NG2). The new function-blocking α11 antibody, mAb 203E1, inhibited cell adhesion to collagen I, partially hindered fibroblast-mediated collagen remodeling and obstructed the three-dimensional (3D) migration rates of PDAC myCAFs. Our data demonstrate that integrin α11 is expressed in a subset of non-pericyte-derived CAFs in a range of cancers and suggest that α11β1 constitutes an important receptor for collagen remodeling and CAF migration in the tumor microenvironment (TME)

α11β1 integrin is induced in a subset of cancer- associated fibroblasts in desmoplastic tumor stroma and mediates in vitro cell migration

Integrin α11β1 is a collagen receptor that has been reported to be overexpressed in the stroma of non-small cell lung cancer (NSCLC) and of head and neck squamous cell carcinoma (HNSCC). In the current study, we further analyzed integrin α11 expression in 14 tumor types by screening a tumor tissue array while using mAb 203E3, a newly developed monoclonal antibody to human α11. Different degrees of expression of integrin α11 were observed in the stroma of breast, ovary, skin, lung, uterus, stomach, and pancreatic ductal adenocarcinoma (PDAC) tumors. Co-expression queries with the myofibroblastic cancer-associated fibroblast (myCAF) marker, alpha smooth muscle actin (αSMA), demonstrated a moderate level of α11+ in myCAFs associated with PDAC and HNSCC tumors, and a lack of α11 expression in additional stromal cells (i.e., cells positive for fibroblast-specific protein 1 (FSP1) and NG2). The new function-blocking α11 antibody, mAb 203E1, inhibited cell adhesion to collagen I, partially hindered fibroblast-mediated collagen remodeling and obstructed the three-dimensional (3D) migration rates of PDAC myCAFs. Our data demonstrate that integrin α11 is expressed in a subset of non-pericyte-derived CAFs in a range of cancers and suggest that α11β1 constitutes an important receptor for collagen remodeling and CAF migration in the tumor microenvironment (TME)