Temporal variability of air-water gas exchange of carbon dioxide in clam and fish aquaculture ponds

The growing trend of land-based aquaculture has heightened the significance of comprehensively assessing air-water carbon dioxide (CO2) gas exchange in these inland waters, given their potential impact on carbon neutral strategies. However, temporal variations of partial pressure of CO2 (pCO2) and CO2 flux in clam and fish aquaculture ponds were barely investigated. We assessed the water surface pCO2 in one to five months intervals by deploying a lab-made buoy in three clam ponds and three fishponds located in tropical and subtropical climates. Measurements were conducted over a 24 h period each time, spanning from April 2021 to June 2022, covering the stocking, middle, and harvesting stages of the culture cycle. Diurnal pCO2 variations were dominantly controlled by biologically driven changes in dissolved inorganic carbon and total alkalinity (~97 %), while temperature and salinity effects were minor (~3 %). Clam ponds acted as a sink of atmospheric CO2 during stocking stages and transitioned to a source during middle to harvesting stages. In contrast, fishponds acted as a source of atmospheric CO2 throughout culture cycles and CO2 flux strengthened when reaching harvesting stages. Overall, clam ponds acted as a weak sink for atmospheric CO2 (-2.8 ± 17.3 mmol m-2 d-1), whereas fishponds acted as a source (16.8 ± 21.7 mmol m-2 d-1). CO2 emission was stronger during daytime coinciding with higher windspeeds compared to nighttime in fishponds. We suggest incorporating high temporal resolution measurements to account for diurnal and culture-stage variations, enabling more accurate estimates of air-water CO2 flux in aquaculture ponds. Moreover, the findings of this study highlight the importance of feeding, aeration, and biological activities (photosynthesis, remineralization, and calcification) in controlling the air-water CO2 flux in aquaculture ponds and such information can be used in implementing better strategies to achieve carbon neutral goals.

Ocean acidification increases inorganic carbon over organic carbon in shrimp's exoskeleton

Ocean acidification (OA) may either increase or have a neutral effect on the calcification in shrimp's exoskeleton. However, investigations on changes in the carbon composition of shrimp's exoskeletons under OA are lacking. We exposed juvenile Pacific white shrimps to target pHs of 8.0, 7.9, and 7.6 for 100 days to evaluate changes in carapace thickness, total carbon (TC), particulate organic carbon (POC), particulate inorganic carbon (PIC), calcium, and magnesium concentrations in their exoskeletons. The PIC: POC ratio of shrimp in pH 7.6 treatment was significantly higher by 175 % as compared to pH 8.0 treatment. Thickness and Ca% in pH 7.6 treatment were significantly higher as compared to pH 8.0 treatment (90 % and 65 %, respectively). This is the first direct evidence of an increased PIC: POC ratio in shrimp exoskeletons under OA. In the future, such changes in carbon composition may affect the shrimp population, ecosystem functions, and regional carbon cycle.

[Expressions of MPV, P-LCR and NLR in patients with novel coronavirus disease 2019]

To provide new ideas for clinical diagnosis and treatment of coronavirus disease 2019 (COVID-19), this study explore the expression level and prognostic value of platelet parameters in mild, moderate and severe COVID-19. This is a retrospective analysis. From January to May 2020, a total of 69 patients who were diagnosed with COVID-19 in the Third Central Hospital and the Jinnan Hospital (both situated in Tianjin) were enrolled in the disease group. According to the severity, these patients were divided into mild group (15 cases), moderate group (46 cases), and severe group (8 cases). In the same period, 70 non-infected patients were enrolled in control group. The level of white blood cell count (WBC), absolute neutrophil count (NEU#), absolute lymphocyte count (LY#), neutrophil-lymphocyte ratio (NLR), red blood cell count (RBC), hemoglobin (Hb), platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW), and platelet-large contrast ratio (P-LCR) before and after treatment were analyzed. Binary logistic regression analysis is used to establish a mathematical model of the relationship between these indexes and the outcome of severe COVID-19 patients. The receiver operating characteristic(ROC) curve is used to further explore the prognosis value of MPV, P-LCR, NLR separately and jointly in COVID-19 patients. Compare to the control group, WBC and NE# increase (Z=-5.63, P<0.01;Z=-9.19,P<0.01) and LY# decrease (Z=-9.34, P<0.01) in the severe group; NLR increase with the aggravation of the disease, there is significant difference between groups (Z=17.61, P<0.01); PLT, PDW, MPV and P-LCR decrease with the aggravation of the disease, there is significant difference between groups (Z=9.47, P<0.01; Z=11.41, P<0.01; Z =16.76, P<0.01; Z=13.97, P<0.01). Binary logistic regression analysis shows MPV, P-LCR and NLR have predictive value for severe COVID-19 patients. There is a negative correlation between MPV, P-LCR and severe COVID-19 patients (OR=1.004, P=0.034; OR=1.097, P=0.046). There is a positive correlation between NLR and severe COVID-19 patients (OR=1.052, P=0.016). MPV and P-LCR of patients with good prognosis after treatment were significantly higher than those before treatment (Z=-6.47, P<0.01; Z=-5.36, P<0.01). NLR was significantly lower than that before treatment (Z=-8.13, P<0.01). MPV and P-LCR in poor prognosis group were significantly lower than those before treatment (Z=-9.46, P<0.01; Z=-6.81, P<0.01). NLR was significantly higher than that before treatment (Z=-3.24, P<0.01). There were significant differences between good and poor prognosis groups before and after treatment in MPV, P-LCR and NLR (P<0.01). Combination of these three indexes, ROC shows the AUC is 0.931, the sensitivity is 91.5%, the specificity is 94.1%, the positive predictive value is 88.9%, and the negative predictive value is 87.4%, which is better than any of these indexes separately. Changes in these parameters are closely related to clinical stage of COVID-19 patients. MPV, P-LCR and NLR are of great value in the prediction and prognosis of severe COVID-19 patients.

New concept for cancer screening

Prevention of cancer mortality can be achieved by two main routes: (1) detection of precancerous lesions and preventing their progression to cancer, and (2) detecting cancers at an early stage when they are still amenable to curative treatment. Early detection of cancer is dependent on the population being well-informed about cancer, and about how to carry out self-examination as a preliminary screen (followed by a full clinical examination in the event of suspicious symptoms). In this paper the warning signs that the population should be taught to look out for are discussed. Superficial observation and palpation can be used for surface tumours (which comprise 10-15% of the total). A further 60-70% of tumours are of the digestive tract, respiratory tract or urogenital tract. For these, it is argued that a simple occult blood test could be used as a self-administered screening test. Data are presented to show that this is a practicable way for the general population to detect early signs of cancer or pre-cancer, with a high yield of clinically significant results in the occult blood positive persons.

Screening of esophageal and gastric cancer by occult blood bead detector

A previously described bead method used to detect blood is simple, cheap, and effective; it can be repeated periodically. In 11 provinces in China, 233,825 persons (age range, 30-70 years) were screened. A positive occult blood test result was found in 28,557 persons (12%). Of these, 16,918 underwent a gastroscopy, resulting in the detection of 581 cancers that were located in similar frequencies in the esophagus, gastric cardia, and gastric body; 70% of the lesions were in an early or moderately advanced stage. Among 119 patients with early-stage cancer, the 3-year survival rate was 98.3%. After preliminary screening of cancer, the 4-year follow-up found a mortality rate in the group with negative occult blood test results that was only 25% of that of the positive group. Preliminary yearly screening would detect more early cancers and fewer advanced cancers. The mortality rate of esophageal and gastric cancer might be reduced drastically.

Screening for upper digestive tract cancer with an occult blood bead detector. Investigation of a normal north China population

Screening of the general population for cancer of the upper digestive tract using an occult blood bead detector supplemented by fibergastroscopy was able to detect 126 cancers of the esophagus, gastric cardia, and stomach. This screening was carried out in two of the high-risk areas, Yangzhong and Wun counties, located in central eastern and north China. The occult blood bead detector, swallowed and retained in the stomach for 3 minutes, was able to sort out the suspected persons by its coloration from sky blue (+) to dark blue ( ) on removal. The subsequent fibergastroscopy could make a definite diagnosis by biopsy specimen. A preliminary trial performed on patients with established cancers was 100% (18 of 18) positive for stomach cancer and 81% (13 of 16) positive for esophageal cancer. A public survey of the high-risk areas, screening 38,073 normal persons ranging in age from 35 to 70 years, showed positive results in 9204 (24.2%) persons. Subsequent fibergastroscopy carried out in 4023 occult blood bead detector positive persons showed 126 cancers (41 of the esophagus, 46 of the gastric cardia, and 39 of the stomach). Factors influencing the cancer detection rate were sex, age, and degree of positivity of the occult blood bead detector test. Seventy per cent (89 of 126) of the cancers discovered were in an early stage. The occult blood bead detector costs the primary screened person only 30 cents and may be practical for the large-scale screening of cancer of the upper digestive tract in developing areas.

Screening for upper digestive tract cancer with an occult blood bead detector. Investigation of a normal north China population

Screening of the general population for cancer of the upper digestive tract using an occult blood bead detector supplemented by fibergastroscopy was able to detect 126 cancers of the esophagus, gastric cardia, and stomach. This screening was carried out in two of the high-risk areas, Yangzhong and Wun counties, located in central eastern and north China. The occult blood bead detector, swallowed and retained in the stomach for 3 minutes, was able to sort out the suspected persons by its coloration from sky blue (+) to dark blue ( ) on removal. The subsequent fibergastroscopy could make a definite diagnosis by biopsy specimen. A preliminary trial performed on patients with established cancers was 100% (18 of 18) positive for stomach cancer and 81% (13 of 16) positive for esophageal cancer. A public survey of the high-risk areas, screening 38,073 normal persons ranging in age from 35 to 70 years, showed positive results in 9204 (24.2%) persons. Subsequent fibergastroscopy carried out in 4023 occult blood bead detector positive persons showed 126 cancers (41 of the esophagus, 46 of the gastric cardia, and 39 of the stomach). Factors influencing the cancer detection rate were sex, age, and degree of positivity of the occult blood bead detector test. Seventy per cent (89 of 126) of the cancers discovered were in an early stage. The occult blood bead detector costs the primary screened person only 30 cents and may be practical for the large-scale screening of cancer of the upper digestive tract in developing areas.

[Occult blood detector for the upper G-I tract. I. A preliminary application in cancer screening]

The traditional chemical detection of small amount of blood in the stool can not tell whether the original bleeding site is in the upper or lower part of the G-I tract. The occult blood detector, designed by the authors, having a diameter of 8 mm, can easy be swallowed into the stomach with 30 to 50 ml of water. After remaining for 3 minutes in the stomach, it is pulled out by the patient himself and its coloration read to reveal the degree of bleeding. It can be used either by the medical personnel or the patient himself, at home, for the purpose of detecting minute bleeding in the upper G-I tract and for cancer screening in the high risk population. This detector gave a positive rate of 95% in patients with malignancies in the upper gastrointestinal tract. It is highly acceptable for its lack of discomfort during application. In cancer screening, it gave a positive rate of 5% to 10% in 10000 high risk persons. Those positive in this test showed a high incidence of gastric or esophageal cancers as proved by gastroscopy. This detector is being manufactured and sold by the Baiyunshan Pharmaceutical Factory, Guangzhou, Guangdong Province. Other papers concerning this topic are to be published.