Extraction of underwater fragile artifacts: research status and prospect

There are still many difficulties in the recovery and long-term preservation of underwater archaeological artifacts, in situ preservation should be the first choice before further procedures are considered. However, the materials, preservation status, and preservation environment of underwater artifacts are diverse, resulting in many fragile artifacts facing difficult situations. In order to prevent serious damage, it is a safe protective strategy to preserve them in a controlled environment for a long time after excavation. Extraction and transfer of fragile cultural relics are vital parts of this strategy. Due to the complexity of the underwater environment and the vulnerability of fragile artifacts, safety in extraction and transfer still faces enormous challenges. Researchers have developed new materials and technologies to tackle this problem. This paper focuses on introducing and developing prospects to different preservation techniques for fragile artifacts from underwater sites.

A novel pneumococcal surface protein K of nonencapsulated Streptococcus pneumoniae promotes transmission among littermates in an infant mouse model with influenza A virus co-infection

We established an infant mouse model for colonization and transmission by nonencapsulated Streptococcus pneumoniae (NESp) strains to gain important information about its virulence among children. Invasive pneumococcal diseases have decreased dramatically since the worldwide introduction of pneumococcal capsular polysaccharide vaccines. Increasing prevalence of non-vaccine serotypes including NESp has been highlighted as a challenge in treatment strategy, but the virulence of NESp is not well understood. Protective strategy against NESp colonization and transmission between children require particularly urgent evaluation. NESp lacks capsules, a major virulent factor of pneumococci, but can cause a variety of infections in children and older people. PspK, a specific surface protein of NESp, is a key factor in establishing nasal colonization. In our infant mouse model for colonization and transmission by NESp strains, NESp could establish stable nasal colonization at the same level as encapsulated serotype 6A in infant mice, and could be transmitted between littermates. Transmission was promoted by NESp surface virulence factor PspK and influenza virus co-infection. However, PspK-deletion mutants lost the ability to colonize and transmit to new hosts. Promotion of NESp transmission by influenza was due to increased susceptibility of the new hosts. PspK was a key factor not only in establishment of nasal colonization, but also in transmission to new hosts. PspK may be targeted as a new candidate vaccine for NESp infection in children.

Study of Crater in the Gobi Desert Induced by Ground Explosion of Large Amounts of TNT Explosive up to 10 Tons

Explosion craters on the ground surface induced by contact or near-field explosions have important implications, which can be used to assess blast consequences, guide the design of the explosion, or develop a protective strategy. In this study, to understand the crater characteristics induced by the contact explosion of large weight explosives, four field contact explosion tests were conducted on the surface of the Gobi Desert with large TNT charge weights of 1 ton, 3 tons, and 10 tons (test conducted twice). Cratering on the ground surface generated by large amounts of explosives was measured and evaluated, including the shape, depth, and diameter. A fine-mesh numerical model was developed and validated on the AUTODYN software platform, and a detailed parametric study was performed on the resulting craters. The effects of sand and gravel density, initiation method, shear modulus, and failure criteria were analyzed and discussed. An energy conversion coefficient was determined, and the corresponding theoretical equations were derived to predict the dimensions of the craters resulting from the large weight contact explosion. The calculated cratering characteristics were consistent with previous data and hence can be used in future engineering applications.

Neuroprotective Effect of Fucoxanthin against Intracerebroventricular Streptozotocin (ICV-STZ) Induced Cognitive Impairment in Experimental Rats

Background: Alzheimer's disease (AD) is a neurological disorder characterized by loss of memory and cognitive functions caused by oxidative stress, neuroinflammation, change in neuro- transmitter levels, and excessive deposition of Aβ(1–42) plaques. Fucoxanthin is a carotenoid with potential antioxidant, anti-inflammatory, and neuroprotective actions. Objective: In the present study, fucoxanthin was employed as a protective strategy in Intracere- broventricular Streptozotocin (ICV-STZ) induced experimental model of cognitive impairment. Methods: STZ was injected twice ICV (3 mg/kg) on alternate days 1 and 3, and Wistar rats were evaluated for the memory analysis using Morris water maze and elevated plus-maze. Fucoxanthin at low 50 mg/kg, p.o. and high dose 100 mg/kg, p.o. was administered for 14 days. All animals were sacrificed on day 29, and brain hippocampus tissue after isolation was used for biochemical (MDA, nitrite, GSH, SOD and Catalase), neuroinflammatory (TNF-α, IL-1β, and IL-6), neurotrans- mitters (ACh, GABA Glutamate), Aβ(1–42) and Tau protein measurements. Results: STZ-infused rats showed significant impairment in learning and memory, increased oxida- tive stress (MDA, nitrite), reduced antioxidant defense (GSH, SOD and Catalase), promoted cy- tokine release, and change in neurotransmitter levels. However, fucoxanthin improved cognitive functions, restored antioxidant levels, reduced inflammatory markers dose-dependently, and res- tored neurotransmitters concentration. Conclusion: The finding of the current study suggests that fucoxanthin could be the promising compound for improving cognitive functions through antioxidant, anti-inflammatory, and neuropro- tective mechanisms, and inhibition of acetylcholinesterase (AChE) enzyme activities, Aβ(1–42) accu- mulation, and tau protein.

Preferred Limb Reaction, Swing and Recovery Step Times between Subjects with and without Chronic Low Back Pain

A compensatory stepping strategy following repeated perturbations may compromise dynamic balance and postural stability. However, there is a lack of study on preferred limb reaction, swing, and step time adjustments. The purpose of this study was to investigate limb reaction, swing, and recovery step times following repeated trip perturbations in individuals with and without non-specific chronic low back pain (LBP). There were 30 subjects with LBP and 50 control subjects who participated in the study. The limb reaction, swing, and recovery step times (s) were measured following treadmill-induced random repeated perturbations (0.12 m/s velocity for 62.5 cm displacement), which caused subjects to move forward for 4.90 s. Both groups demonstrated a significant interaction of repetitions and times (F = 4.39, p = 0.03). Specifically, the recovery step time was significantly shorter in the LBP group during the first trip (t = 2.23, p = 0.03). There was a significant interaction on repetitions and times (F = 6.03, p = 0.02) in the LBP group, and the times were significantly different (F = 45.04, p = 0.001). The initial limb reaction time of the LBP group was significantly correlated with three repeated swing times to avoid falls. The novelty of the first trip tends to enhance a protective strategy implemented by the LBP group. Although limb preference did not demonstrate a significant difference between groups, the LBP group demonstrated shorter recovery step times on their preferred limb initially in order to implement an adaptive strategy to avoid fall injuries following repeated perturbations.

Impact on the Service Volume of a Single Hand Surgery Center during the COVID-19 Pandemic Period in Daegu

Purpose: We investigated what changes occurred at single hand surgery center during the coronavirus disease 2019 (COVID-19) pandemic in Daegu, Korea using patient data of 4 years (2018–2021).Methods: This is a single-center retrospective study of patients visiting our center during the COVID-19 pandemic for 4 years (January 22 to May 6). Service volumes (SVs) including the number of in/outpatient, emergency room, elective, and emergency surgery were analyzed. During the peak period of the COVID-19 (February 24 to March 9, 2020), patient’s demographics, injury mechanism, and place of injury of hand trauma were analyzed.Results: SVs were significantly reduced in 2020 as compared with other years. The SVs except for the number of emergency surgeries have recovered after 2 months from the first confirmed case of COVID-19 in Daegu, Korea. At the peak period, the effect of COVID-19 was weak on emergency room-related SVs. In addition, a daily number of in/outpatients and elective surgeries had a statistically significant negative correlation with the number of COVID-19 confirmed (p<0.05). During the peak period, superficial laceration increased and finger and wrist fractures decreased. The number of cases occurring in workplace increased, however, occurring outside during daily life decreased.Conclusion: COVID-19 pandemic greatly reduces service volume in our center. Thorough protective strategy from COVID-19 such as personal protective equipment was essential for early recovery of hospital functions during the pandemic. In addition, manpower for the emergency room must be preserved during the pandemic. The results of our study, which reported SVs through the pandemic will help maintain the function of hand surgery centers.

Amelioration of Diabetic Nephropathy by Targeting Autophagy via Rapamycin or Fasting: Relation to Cell Apoptosis/Survival

Autophagy has been demonstrated to have a beneficial effect on diabetic nephropathy (DN). Rapamycin, an inhibitor of mTOR, was shown to stimulate β-cell autophagy. However, its effects on preventing or ameliorating DN is unclear, and its effects are worth studying. As fasting is now an attractive protective strategy, we aim to compare its effect to rapamycin effects on pancreatic and renal cells. Twenty-eight adult male Wistar Albino rats were randomly divided into four groups, using streptozotocin (STZ) to induce diabetes mellitus (DM). Autophagy was induced by two ways; rapamycin or fasting. The extent of autophagy and apoptosis were investigated by measuring the level of LC3B and p53 proteins, respectively, in pancreatic and kidney tissues using Western blotting (WB) technique and imaging the renal cells under transmission electron microscope. The efflux transporter P-glycoprotein was quantified by WB as well. Rapamycin-induced autophagy occurred concurrently with apoptosis. On the other hand, fasting supported P-glycoprotein recovery and renal cell survival together with disabling β-cells apoptosis. In conclusion, this study provides a potential link between rapamycin or fasting for the cross-regulation of apoptosis and autophagy in the setting of cell stress as DN. Unlike rapamycin, fasting enhanced the active expression of ABCB1 efflux protein, providing insights on the potential ameliorative effects of fasting in DN that require further elucidation.