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Chapter 2: Primary Hyperparathyroidism: diagnosis.

Primary hyperparathyroidism is now predominantly an asymptomatic pathology, as blood calcium assay has become systematic. Diagnosis therefore requires screening for target organ damage when this is not already indicative of primary hyperparathyroidism. Classical clinical manifestations include bone, kidney and muscle signs, and are characterized by reversibility after parathyroid surgery. Their presence requires blood calcium assay. Non-classical manifestations include cardiovascular, digestive and neuropsychological signs, which are not known to be reversible after surgery. Positive diagnosis is biological, based on a parathyroid hormone value that is inappropriate to the blood calcium value. The typical form combines hypercalcemia, elevated parathyroid hormone and increased calciuria or calcium excretion fraction. Atypical forms combine either hypercalcemia and normal parathyroid hormone level, or normal calcemia with increased parathyroid hormone level, not necessarily secondary to another cause, such as 25(OH) vitamin D deficiency. The oral calcium loading test and the Pro-FHH score are contributive to diagnosis in atypical forms.

Clinical Trial to Evaluate Safety and Efficacy of Thinqure20 (A Herbal Composition) in the Treatment and Prophylaxis of Novel Coronavirus and Testing its In vitro- Potential against MS2 Bacteriophagae, Corona Virus, Influenza Virus and Mucor racemosus

Background and Objective: Thinqure20 is a polyherbal, reverse-pharmacology-based formulation that contains Piper longum, Piper nigrum, Zingiber officinale, and rock salt as active ingredients. It is designed to work as an effective antiviral agent and also as a preventive measure against SARS-CoV-2. Clinical and non-clinical studies have established significant safety efficacy and tolerability of Thinqure20 formulation in the treatment of COVID-19 infection. Methods: In vivo human study was conducted on COVID-19 patients for 5 days. A total of 30 Covid-19 patients (n = 30) were enrolled. In vitro, cell line studies were also carried out to evaluate the potential effectiveness of Thinqure20 polyherbal formulation as an antiviral, antifungal, and Angiotensin- Converting Enzyme 2 (ACE2) inhibition. Results: Human studies have demonstrated a mean percentage of reduction in viral load from baseline to end of the study visit which was found to be 75.4%. The minimum and maximum reduction in viral load was found to be 59.3% and 100%, respectively. Viral load testing was carried out by Reverse Transcriptase-quantitative Polymerase Chain Reaction (RT-qPCR) test. In vitro studies of Thinqure, 20 extracts showed potential antiviral activity against MS2 bacteriophage, influenza, and human coronavirus, antifungal activity against Mucor racemosus, and significant ACE2 receptor inhibition. Conclusion: Thinqure20, a polyherbal formulation, is a potentially effective antiviral agent against non-enveloped viruses (MS2 bacteriophage), enveloped viruses (influenza and human coronavirus), and antifungal agent against mucor strains. It is also proven to be effective in the treatment of COVID-19 and can be attributed to an early recovery by the reduction in viral load.

The Response of Pressure-Cast-In-Situ Pile with Spray-Expanded Frustum Using Field Static Load Tests

The Response of Pressure-Cast-In-Situ Pile with Spray-Expanded Frustum Using Field Static Load Tests

Bending performance and design of reinforced concrete ribbed bridge deck slabs retrofitted with steel-plate reinforcement

ABSTRACT This study aimed to assess the bending performance and design of reinforced concrete ribbed bridge deck slabs with steel-plate reinforcement. Two reference members and three steel-plate reinforcements were designed for four-point bending loading tests, numerical simulations, and theoretical analyses. Steel-plate reinforcement improves the flexural load bearing capacity and stiffness of the bridge deck slab and effectively controls crack development, compared to old bridge reconstruction requirements. The bridge deck is best stressed when the bolt (M12 mm × 200 mm) spacing is 0.8 times the slab thickness. To prevent brittle damage to the bridge deck, a steel plate with a width of 160 mm and thickness of 10 mm should be used for strengthening. This aligns with engineering practice whereby the bolt shear capacity is used to assess the effectiveness of steel-plate reinforcement in bridge deck slabs. Bolt shear arrangement based on the slip effect and a sufficient increase in the diameter of the bolts at both ends of the steel plate are more appropriate for the bending effect of the bridge deck structure. The results provide a reference for the design of deck slab reinforcement for assembled ribbed bridges.

Study on the Mechanical Characteristics and Degradation Response of Unloading Rocks Surrounding Tunnels in Cold Regions

The excavation of the rock mass at the tunnel entrance in regions characterized by high altitudes and elevated stress levels results in the direct exposure of the surrounding rock to atmospheric conditions. This surrounding rock is subjected to the compounded effects of excavation-induced unloading damage and freeze–thaw erosion, which contribute to the degradation of its mechanical properties. Such deterioration has a negative impact on production and construction operations. Following tunnel excavation, the lateral stress exerted by the surrounding rock at the tunnel face is reduced, leading to a predominance of uniaxial compressive stress. As a result, the failure mode and mechanical behavior of the rock exhibit characteristics similar to those observed in uniaxial loading tests conducted in controlled laboratory environments. This study conducts laboratory-based uniaxial loading and unloading tests, as well as freeze–thaw tests, to examine the strength, deformation characteristics, and fracture attributes of unloading sandstone subjected to freeze–thaw erosion. A damage deterioration model for unloading sandstone under uniaxial conditions is developed, and the patterns of damage response are further analyzed through the identification of compaction points and the definition of damage response points. The results indicate that (1) as the degree of freeze–thaw erosion increases, the failure threshold of the sandstone significantly decreases, with the residual rock fragments on the fracture surface transitioning from hard and sharp to soft and sandy; (2) freeze–thaw erosion has a pronounced negative impact on the cohesion of the sandstone, while the reduction in the internal friction angle is relatively moderate; and (3) the strain induced by damage following three, six, and nine freeze–thaw cycles exhibits a gradual decline and appears to reach a state of stabilization when compared to conditions without freeze–thaw exposure. Investigating the mechanical properties and deterioration mechanisms of the rock in this specific context is crucial for establishing a theoretical foundation to assess the stability of the tunnel’s surrounding rock and determine the necessary support measures.

Computerized Tomography for Diagnosing Traumatic Arthrotomies of the Ankle.

Owing to the risk for septic arthritis, traumatic arthrotomies are an urgent surgical problem for the treating orthopaedic surgeon. Traditionally, diagnosis is with the saline load test (SLT), although in the awake patient is an invasive and potentially painful procedure. While computerized tomography (CT) has been shown to be a reliable diagnostic tool for traumatic arthrotomies of other joints, its role has only recently been investigated in the setting of ankle arthrotomy. Eight fresh-frozen mid-tibia ankle cadaveric specimens were included for study. Baseline CT scans were performed to confirm intact ankle joint capsules with absence of intra-articular air. Ankle arthrotomies were performed under fluoroscopic guidance with vertical 1 cm incisions made at the anteromedial or anterolateral portals. After arthrotomy, all ankles underwent a second CT scan, and images were evaluated for the presence of intra-articular air. Finally, SLT was performed and the volume of saline required for extravasation was recorded. Of 8 ankles, 100% (n = 8) demonstrated intra-articular air on CT scan following arthrotomy. Computerized tomography scan and SLT both demonstrated 100% sensitivity and specificity for diagnosing ankle arthrotomies. Average saline volume necessary for extravasation (and positive SLT) was 4 mL (range: 2-7 mL) and did not differ by foot position. In this small cadaveric study, CT scan and SLT were both able to detect 100% (n = 8) of traumatic ankle arthrotomies with 100% sensitivity and specificity. Further comparative study of CT scan and SLT for detection of traumatic ankle arthrotomy in a clinical setting is warranted. Level IV.

Horizontal Cyclic Bearing Characteristics of Bucket Foundation in Sand for Offshore Wind Turbines

During the service period, the offshore wind turbine foundation mainly bears the wind load from the upper structure and the periodic loads such as wave load and sea currents from the lower structure. Long-term cyclic loads have an important impact on the cumulative deformation, foundation stiffness changes, and horizontal ultimate bearing capacity of the offshore wind turbine bucket foundation. This paper conducts cyclic loading tests on mono-bucket foundations under unidirectional and multidirectional cyclic loading conditions based on the multidirectional intelligent cyclic loading system of offshore wind turbine foundations and analyzes the cumulative effects of the loading direction, vertical load, and drainage status on the mono-bucket foundation during the cyclic loading process, effects of rotation angle, cyclic stiffness, and monotonic bearing capacity of foundation after cycles. The research results show that multidirectional cyclic loading significantly reduces the cyclic cumulative rotation angle of the mono-bucket foundation, and the maximum reduction rate can reach more than 50%. After unidirectional and multidirectional cyclic loading, the bearing capacity of the bucket foundation can be increased by up to 30% and 20%, respectively. At the same time, this paper proposes calculation formulas for vertical load, number of cyclic loading, and normalized cumulative rotation and establishes a calculation method for vertical load and bearing capacity of the foundation after cycles.

Physical Test and Numerical Analysis of Damage Mechanism of Rocky Foundation with Parallel Structural Surfaces

The growth of rock structural surfaces makes the deformation and stability analysis of rock pits more complex and challenging than that of soil pits. To investigate the damage mechanism of this foundation and provide ideas for foundation support, the paper constructed a simplified model by approximate plane analysis and dimensionless analysis of the similarity principle. The physical model was constructed from a mixture of materials, and then foundation excavation and loading tests were completed. The strain value of the strain gauges increased in stages in the range of 0–250. Excavation of the structural surface resulted in an increased number of deformation mutations. This type of rocky foundation damage underwent three stages: overburden crack development, cumulative deformation of the S-S, and collapse of the sliding body. Furthermore, numerical simulations corresponding to the physical model tests were set and used to validate and complement the physical tests. When the line loads reached 70.83 kN/m and 127.5 kN/m, the plastic zone of the structural surface was completely penetrated and the sliding body collapsed. The results of the studies can serve as a useful reference and guide for the excavation and support design of real-world rock foundation projects that are similar.

Optimize the Design of a Lower Limb Rehabilitation Robot Based on a Spring Assisted System

This paper presents the design and optimization of a lower limb rehabilitation robot featuring a spring-assisted system aimed at improving energy efficiency and user adaptability. The robot incorporates a spring and motor at the knee joint, enabling key functions such as sitting and standing, while providing shock absorption and energy-saving benefits. To further enhance efficiency, a genetic algorithm was used to optimize the key parameters, resulting in a significant reduction in motor energy consumption. The performance was evaluated by comparing the energy usage before and after optimization under varying load conditions, with clear improvements observed. Additionally, load testing was conducted to determine the maximum load the exoskeleton can support within the motor's torque limits. The results demonstrate the design's ability to reduce motor strain while accommodating different user needs. This work emphasizes the potential of spring-assisted exoskeletons in rehabilitation therapy, offering improved performance and practicality. Future improvements should focus on enhancing motion control precision and increasing the load-bearing capacity, ensuring the technology meets growing rehabilitation demands globally.

On-site Load Test and Numerical Analysis of Existing Cantilever-Erection Prestressed Concrete Bridge with Central Hinge for Structural Safety Assessment: Case Study of Minquan Bridge

On-site Load Test and Numerical Analysis of Existing Cantilever-Erection Prestressed Concrete Bridge with Central Hinge for Structural Safety Assessment: Case Study of Minquan Bridge

Deformation mechanism and damage energy evolution of coal body under different gas pressures based on the energy principle

With increasing mining depth, the coal pillars of a coal mine will be in a stressful environment characterized by high gas pressures and unidirectional loading. To investigate the damage evolution characteristics and energy evolution mechanism of coal pillars loaded in a gas pressure environment, a uniaxial compression test was performed on a coal body under different gas pressures using a load testing apparatus for gas-containing coal rocks. The obtained results showed that the mechanical properties of the coal body varied with the gas pressure. Specifically, the peak strain, compressive strength, and elastic modulus decreased with increasing gas pressure; the higher the gas pressure, the lower the conversion rate of the elastic strain energy in the elastic deformation stage of the coal body and the lower its total input energy. With increasing gas pressure, the damage threshold of the coal body decreased, whereas the damage variable corresponding to the peak value, as well as the damage threshold value, increased. According to the theory of continuous damage mechanics, an ontological damage model of the coal body under different gas pressures was established based on the principle of minimum energy dissipation, and the rationality of the model was verified through a comparison between the theoretical and experimental data. Our findings can be useful in ensuring the safety of coal mining in terms of preventing gas disasters.

Novel anchor-type proximal femoral nail for the improvement of bone-fixation integrity in treating intertrochanteric fractures: an experimental and computational characterization study

This study introduces a novel anchor-type proximal femoral nail (AT-PFN) to improve the bone-fixation integrity over the standard screw-type nail (SST-PFN). Quasi-static incremental cyclic load test was performed to investigate load-displacement, cumulative deformation energy, time-strain, and backbone curves. The finite element analysis (FEA) was implemented to identify the stress and strain distributions. Additionally, non-destructive dynamic tests were conducted, and the measurements were processed using statistical pattern recognition, based on vector autoregression and principal component analysis to investigate the nonlinearity due to bone-fixation interface. The results demonstrate that the AT-PFN significantly improves the bone-fixation integrity compared to SST-PFN.

Numerical and Experimental Investigation of an Extradosed Cable-Stayed Bridge in Urban Rail Transit Under Dynamic Train Load

With the urban rail transit construction boom, more and more extradosed cable-stayed bridges have been built and put into service in the urban rail transit lines, due to the advantages of aesthetic appearance and high stiffness. There are distinct dynamic characteristics of the metro train and extradosed cable-stayed bridge system, which have rarely been explored. This paper presents the numerical and experimental investigation of an extradosed cable-stayed bridge under dynamic train load in urban rail transit with the maximum span among its type of bridge in China. Three vehicle modes with different degrees of freedom and two bridge finite element models are adopted to perform the dynamic analysis of the metro train and extradosed cable-stayed bridge system. Moreover, the bridge is instrumented in a comprehensive field measurement campaign including ambient vibration testing, static load testing, and dynamic load testing. The collected modal parameters and static and dynamic responses of the bridge are employed to validate the established numerical models. Dynamic characteristics of the analyzed bridge are subsequently explored. In particular, dynamic effects of the main components including the main girder, pylons, and inclined cables are examined considering a variety of operational conditions. This study provides an effective method for analyzing the dynamic responses and valuable insights into the dynamic performance of large-span extradosed cable-stayed bridges under metro train load in urban rail transit.

The Effect of Core Filling on Seismic Performance of Pretensioned Centrifugal Spun Concrete Piles with Steel Strands

ABSTRACT Pretensioned centrifugal spun concrete piles with steel strands have been developed to improve the seismic performance of precast-prestressed concrete hollow piles. In this paper, two pile specimens with reinforced concrete infilling were fabricated, and lateral cyclic loading tests were conducted. A finite element model is developed to predict the hysteretic characteristics of core-filled pile specimens. The results show that reinforced concrete infilling improves the cracking pattern and failure mode of piles. Core-filled piles exhibit better structural stability and higher deformability than hollow piles. Reinforced concrete infilling enhances the lateral load-carrying capacity and deformability more significantly than plain concrete infilling.

Analysis of Short Bored Piles in Tropical Soil Under Tension and Compression Load Tests

Analysis of Short Bored Piles in Tropical Soil Under Tension and Compression Load Tests

Modieslab Innovative Concrete Pavement Structure: From Idea through Research to Implementation

In 1996 the Dutch Ministry of Transport, Public Works and Water Management launched the innovation program ‘Roads to the Future’. One of the developed innovative pavement structures is a Modular Pavement Structure called Modieslab. This structure is designed as a bridge and it merely consists of precast concrete elements. Since 2001 several researches were performed. Along the motorway A50 in the Netherlands a low-risk and not heavily loaded test section was constructed and monitored during 16 months. On this test section mainly the functional properties as well as construction and maintenance techniques were investigated. The main findings of this test section are reported. The structural integrity of the structure was investigated by Accelerated Load Testing of another instrumented test section by means of LINTRACK. Some characteristic measurement results are presented. Insight into the structural behaviour of both the total pavement structure and the most critical upper part of it was further obtained by means of 3D finite element modelling. Some typical calculation results are compared to measurement results. Finally the materials research is briefly described. This research concentrates on the porous concrete wearing course. Research is ongoing to find solutions for skid resistance and ravelling problems that occurred to some extent on the test sections. Given the rather positive experiences, both from a technical and an economical point of view, it was decided to actually construct an in-service road section of the radically innovative Modieslab pavement structure after only 4 to 5 years of research. Probably this project will be realized in 2005 or 2006 in an area with very poor subsoil.

The Fractal Dimension, Structure Characteristics, and Damage Effects of Multi-Scale Cracks on Sandstone Under Triaxial Compression

To study the influence of the spatial distribution and structure of multi-scale cracks on the mechanical behavior of rocks, triaxial compression tests and cyclic triaxial complete loading and unloading tests were conducted on sandstone, with real-time wave velocity monitoring and CT scan testing. The quantitative classification criteria for multi-scale cracks on sandstone were established, and the constraint effect of confining pressure was analyzed. The crack with a length less than 0.1 mm is considered a small-scale crack, 0.1–1 mm is a medium-scale crack, and larger than 1 mm is a large-scale crack. As the confining pressure increases, the spatial fractal dimension of large-scale cracks decreases, while that of medium-scale cracks increases, and that of small-scale cracks remains stable. The respective nonlinear models of the aspect ratio were established with the length and density of multi-scale cracks. The results indicate significant differences in the effects of cracks of different scales on rock damage. The distribution density of medium-scale cracks in the failed specimen is higher, which is the main reason to produce damage. The small-scale cracks mainly originate from relatively uniform initial cracks in rocks, mainly distributed in medium-density and low-density areas. The results of this research provide important insights into how to quantitatively evaluate the damage of rocks.

Mechanical Design of Ultra-Thin White-Topping with High Strength Concrete Panel

An ultra-thin white-topping structure with high strength concrete panel (HSCWT) was developed. In the structure, 30 mm thick concrete panels, which are produced from steel fiber reinforced concrete with a flexural strength of 20 MPa, are placed on an existing asphalt pavement and the interface between the panels and the asphalt pavement is grouted to bond them. Test pavements of HSC-WT were constructed on an accelerated loading facility and were subject to moving axle loads. After one hundred fifty thousand axles passed over the pavements, although small gaps developed between HSC panels and grout near joints, any severe cracks didn’t develop. Improved textures on the bottom face of panel were found very effective to bond the panel and grout. Although simulation of the loading test with dynamic 3DFEM fairly well represented the strain time histories generated by the travelling axle load, visco-elastic properties of asphalt layer could not clearly identified. Stress analysis with assumed visco-elastic parameters revealed that the stresses in the panel due to axle load are much less than the strength of the HSC panel, if the panel and the grout is fully bonded at the interface. Based on the results, a mechanical design procedure for HSCWT is developed. In the procedure, tensile strains in the underlying asphalt layer are calculated with 3DFEM and fatigue damage of the asphalt layer is estimated from the tensile strains using fatigue curve of asphalt mixture. It was found that not only viscosity of asphalt layer but also vehicle speed significantly affects fatigue life of asphalt layer.

Pavement Flexural Fatigue Capacity, and the influence of Mix Charging Sequence

The durability of concrete pavements is greatly dictated by their capacity to resist fatigue induced by flexural stresses. Known to be a critical factor in fatigue behaviour is the quality (or deterioration under loading) of the bond between the cement paste and aggregate. This paper reports on lab and large-scale trial applications of a range of modified mix charging sequences in terms of their ability to improve the flexural fatigue life of concrete pavements, and also on conventional concrete plastic and hardened properties. Flexural fatigue resistance was assessed using the ASTM C1550 round panel loading test over a range of target failure loads, eg 10² to 106 cycles. Whilst source research was initially focussed on improved distribution of SCMs, this paper demonstrates that similar techniques significantly affect rheology, setting, strength and, in some cases, fatigue capacity and bond quality – all thought to be the result of a modified transition zone (between aggregate and mortar). Importantly, each modified charging sequence was selected or adapted on the basis that such new charging techniques, if shown to be beneficial, could be readily adapted to the common dry batch concrete plants already in use in readymix batching and on-site batching or mixing plants. This study will show that, for a matched mix design, the RILEM method of batching improves the fatigue resistance (and life) of a typical Australian pavement quality concrete by 23% when compared with the conventional batching sequence presently used by premixed and typical on-site concrete batch plants.

A Constitutive Model for Anisotropic Sand Considering Fabric Evolution Under Proportional and Non‐Proportional Loadings

ABSTRACTA critical state plasticity model is proposed to describe the anisotropic sand behaviour under both proportional and non‐proportional loading conditions. An evolving fabric tensor is introduced into the model to reflect the influence of fabric anisotropy on the stress‐strain relation of sand. By employing a fabric‐dependent plastic flow direction, the non‐coaxial response can be simulated in a simple way. A non‐proportional loading mechanism is incorporated to consider the plastic deformation induced by the stress increment tangential to the yield surface. The influence of accumulative plastic strain on the dilatancy function and plastic modulus is properly considered, enabling the model to reasonably capture the evolutions of volumetric and deviatoric strains under both drained and undrained principal stress axes rotation. The model was validated based on the simulations of experimental results for monotonic loading and pure principal stress axes rotation tests covering a wide range of conditions.