An Alternative Hot Start PCR Method Using a Nuclease-Deficient ExoIII from Escherichia coli.

The Hot Start polymerase chain reaction (Hot Start PCR) is designed to reduce off-target amplification by blocking DNA polymerase extension at room temperature until the desired temperature is reached. In this study, we investigated a new method of Hot Start PCR that uses a modified Escherichia coli Exonuclease III (EcoExoIIIM) by substituting residues in the DNA-binding pocket and catalytic center. The results showed that PCR amplification yield and specificity were significantly promoted by the addition of EcoExoIIIM. We hypothesize that non-specific binding of primers at room temperature is prevented by binding of the primed template by EcoExoIIIM, which is then released from the DNA by heat denaturation before the first PCR cycle. Through this mechanism, PCR would be enhanced by reducing off-target extension at room temperature

An Alternative Hot Start PCR Method Using a Nuclease-Deficient ExoIII from Escherichia coli

Abstract(#br)The Hot Start polymerase chain reaction (Hot Start PCR) is designed to reduce off-target amplification by blocking DNA polymerase extension at room temperature until the desired temperature is reached. In this study, we investigated a new method of Hot Start PCR that uses a modified Escherichia coli Exonuclease III (EcoExoIIIM) by substituting residues in the DNA-binding pocket and catalytic center. The results showed that PCR amplification yield and specificity were significantly promoted by the addition of EcoExoIIIM. We hypothesize that non-specific binding of primers at room temperature is prevented by binding of the primed template by EcoExoIIIM, which is then released from the DNA by heat denaturation before the first PCR cycle. Through this mechanism, PCR would be..

The Clinical Clues of Pulmonary Alveolar Proteinosis: A Report of 11 Cases and Literature Review

Pulmonary alveolar proteinosis (PAP) is a rare interstitial lung disease characterized by the abnormal alveolar accumulation of surfactant components. The diagnosis of PAP can be easily missed since it is rare and lacks specific clinical symptoms. It is of great importance to have a better understanding of the crucial clue to clinically diagnose PAP and take PAP into consideration in the differential diagnosis of interstitial pulmonary diseases or other diseases with similar manifestations. Here, we analyze the clinical characteristics of 11 cases of PAP patients in local hospital and review the relevant literature in order to provide more information in diagnosis and management of PAP. In our observation, cyfra21-1 and neuron-specific enolase (NSE) known as tumor markers probably can be useful serum markers for diagnosis of PAP. As for the method of pathologic diagnosis, open-lung biopsy was the gold standard but now it is less required because findings on examination of bronchoalveolar lavage fluid (BALF) can help to make the diagnosis. We also have deep experience about when and how to carry out lung lavage

Relationship between Income and Mental Health during the COVID-19 Pandemic in China

Mental health problems represent one most pressing concerns in the world, which produce costly consequences for individuals, families and society as a whole. One of the determinants on mental health during the COVID-19 pandemic is income. To complement relevant research and provide valuable recommendations for governments and societies, this study investigates the nexus between income and mental health in China by employing 8049 observations from the 2020 China Family Panel Studies. Using ordinary least squares regression we find the significant positive relationship between income and mental health, and estimate the effect of income on mental health. Furthermore, this effect is heterogeneous depending on individuals’ education level and registered residence type. Finally, individuals’ economic status and happiness are shown to be the potential mechanism through which the effect of income on mental health operates

Coupled nutricline and productivity variations during the Pliocene in the western Pacific warm pool and their paleoceanographic implications

Highlights • Accurate age model during Pliocene for site U1490 established • Co-variant nutricline depth and productivity in WPWP throughout Pliocene • Deeper nutricline and lower productivity during 4.8–3.5 Ma linked to CAS closure • Nutricline shoaling during 3.5–3.0 Ma due to restriction of Indonesian Seaway Abstract The tropical Pacific played an important role in modulating global climate change during the Pliocene. Studies of tropical Pacific sea surface temperatures covering the period from the Pliocene onwards indicate that changes in the thermal mean state over the tropical Pacific can significantly influence global climate feedbacks and connect the high- and low-latitude climates. Tropical productivity fluctuations are a significant mechanism with respect to the operation of the global carbon cycle. Yet, temporal changes in primary productivity are not well constrained in the western Pacific warm pool (WPWP), where the ocean–climate system is not dominated by upwelling systems. Furthermore, the role of nutricline dynamics in forcing productivity over tectonic timescales remains uncertain. Here we use relatively high-resolution foraminiferal carbon isotope records combined with Ba/Ti ratios obtained from International Ocean Discovery Program (IODP) Site U1490 in the WPWP to reconstruct nutricline depth and paleoproductivity over the period 5.1–2.6 Ma. Our records imply that nutricline and productivity variations were closely coupled over tectonic timescales, implying that the dynamics of the nutricline play a significant role in regulating productivity in the WPWP. The deeper nutricline and lower productivity during 4.8–3.5 Ma might have been fostered by the closure of the Central American Seaway through the thickening of the mixed layer in the WPWP. We relate the overall shallower nutricline and increased productivity during 3.5–3.0 Ma to the restriction of the Indonesian Seaway via the enhanced influence and upwelling of high-latitude southern-source waters

Control of H₂S generation in simultaneous removal of NO and SO₂ by rotating drum biofilter coupled with Fe^II(EDTA)

<p>Simultaneous removal of SO₂ and NO from flue gas can be biologically achieved by the rotating drum biofilter with Fe^II(EDTA) as a solvent. One issue related with this process is the generation of H₂S. To control its generation, the pathways of H₂S formation were investigated, and the parametric tests were conducted. The addition of Fe^II(EDTA) (10 mM) increased the removal efficiency of NO and SO₂, while the S²⁻ concentration decreased from 81 to 3.5 mM. The parametric tests showed that the high NO concentration favored the SO₂ removal and significantly inhibited the H₂S generation. High-throughput sequencing showed that the dominant denitrifying bacteria were <i>Pseudomonas</i> (9.09%), and the main sulfate-reducing bacteria were <i>Desulfovibrio</i> (5.84%). The long-term operation confirmed that the system could effectively simultaneous perform biological denitrification and desulfurization, and the H₂S could be controlled.</p

The Clinical Clues of Pulmonary Alveolar Proteinosis: A Report of 11 Cases and Literature Review

Pulmonary alveolar proteinosis (PAP) is a rare interstitial lung disease characterized by the abnormal alveolar accumulation of surfactant components. The diagnosis of PAP can be easily missed since it is rare and lacks specific clinical symptoms. It is of great importance to have a better understanding of the crucial clue to clinically diagnose PAP and take PAP into consideration in the differential diagnosis of interstitial pulmonary diseases or other diseases with similar manifestations. Here, we analyze the clinical characteristics of 11 cases of PAP patients in local hospital and review the relevant literature in order to provide more information in diagnosis and management of PAP. In our observation, cyfra21-1 and neuron-specific enolase (NSE) known as tumor markers probably can be useful serum markers for diagnosis of PAP. As for the method of pathologic diagnosis, open-lung biopsy was the gold standard but now it is less required because findings on examination of bronchoalveolar lavage fluid (BALF) can help to make the diagnosis. We also have deep experience about when and how to carry out lung lavage

Influences of Atlantic Ocean thermohaline circulation and Antarctic ice-sheet expansion on Pliocene deep Pacific carbonate chemistry

Highlights • High-resolution deep-water record for Pliocene western tropical Pacific. • Changes in NADW production at ∼4.6 Ma and ∼2.7 Ma influenced Pacific • These changes controlled a seesaw fluctuation between deep Pacific and Atlantic oceans. • Antarctic ice-sheet/sea-ice expansions influenced deep Pacific • These ice-mass changes resulted in long-term decline during late Pliocene. Abstract Quantifying changes in seawater carbonate chemistry is crucial to deciphering of patterns and drivers of the oceanic carbon cycle and climate change. Here, we present a new deep-water carbonate ion saturation state record for the Pliocene western tropical Pacific, reconstructed from the size-normalized weight of the planktonic foraminifer Trilobatus sacculifer of IODP Site U1490. A steep decline in deep-water occurred at ∼4.6 Ma synchronous to the enhanced production of North Atlantic Deep Water (NADW) related to the closure of the Panamanian Gateway. Subsequently, at the onset of the Northern Hemisphere glaciation at ∼2.7 Ma the weakening of NADW formation resulted in a deep-water peak. The changes in NADW production rate likely controlled a seesaw-like fluctuation in deep-water between the Pacific and Atlantic oceans. During the late Pliocene (∼3.8–2.8 Ma), Antarctic ice-sheet/sea-ice expansions sequestered CO2 in the deep Pacific through ventilation of the deep watermass, leading to a long-term decrease in deep Pacific . We infer that fluctuating NADW production rates at ∼4.6 Ma and ∼2.7 Ma influenced inter-basinal fractionation of deep-ocean carbon between the Atlantic and Pacific, and that deep Pacific carbon storage linked to expansions of Antarctic ice sheet/sea ice contributed to the lowering of atmospheric pCO2 and global cooling during the late Pliocene