Numerical study on non-uniform heat transfer deterioration of supercritical RP-3 aviation kerosene in a horizontal tube

The convective heat transfer of supercritical-pressure RP-3(Rocket Propellant 3)aviation kerosene in a horizontal circular tube has been numerically studied,focusing mainly on the non-uniform heat transfer deterioration along the circumferential direction.The governing equations of mass,momentum and energy have been solved using the pressure-based segregated solver based on the finite volume method.The re-normalization group(RNG)k-εturbulence model with an enhanced wall treatment was selected.Considering the heat conduction in the solid wall,the mechanism of heat transfer deterioration and the buoyancy effect on deteriorated heat transfer were discussed.The evolution of secondary flow was analyzed.Effects of the outer-wall heat flux,mass flux,pressure and tube thermal conductivity on heat transfer were investigated.Moreover,the buoyancy criterion and the heat transfer correlation were obtained.Results indicate that the poor flow performance of near-wall fluid causes the pseudo-film boiling,further leads to the heat transfer deterioration.The strong buoyancy has an effect of enhancing the heat transfer at the bottom of tube,and weakening the heat transfer at the top of tube,which results in the non-uniform inner-wall temperature and heat flux distributions.Decreasing the ratio of outer-wall heat flux and mass flux,increasing the pressure could weaken the heat transfer difference along the circumferential direction,while the effect of thermal conductivity of tube on the circumferential parameters distributions is more complicated.When the buoyancy criterion of(Grq/Grth)max≤0.8 is satisfied,the effect of buoyancy could be ignored.The new correlations work well for non-uniform heat transfer predictions.

Dietary calcium requirements of broilers fed a conventional corn-soybean meal diet from 1 to 21 days of age

Background:The current calcium(Ca)recommendation for broilers is primarily based on studies conducted more than 30 years ago with birds of markedly different productive potentials from those which exist today.And the response indicators in these studies are mainly growth performance and bone ash percentage.Therefore,the present study was carried out to investigate the effect of dietary Ca level on growth performance,serum parameters,bone characteristics and Ca metabolism-related gene expressions,so as to estimate dietary Ca requirements of broilers fed a conventional corn-soybean meal diet from 1 to 21 days of age.Methods:A total of 4201-day-old Arbor Acres male broilers were randomly assigned to 1 of 7 treatments with 6 replicates(10 birds per cage)and fed the corn-soybean meal diets containing 0.60%,0.70%,0.80%,0.90%,1.00%,1.10%or 1.20%Ca for 21 days.Each diet contained the constant non-phytate phosphorus content of about 0.39%.Results:The average daily gain decreased linearly(P<0.001)as dietary Ca level increased.The serum and tibia alkaline phosphatase(ALP)activities,tibia bone mineral density(BMD),middle toe BMD,tibia ash percentage,tibia breaking strength,and tibia ALP protein expression level were affected(P<0.05)by dietary Ca level,and showed significant quadratic responses(P<0.02)to dietary Ca levels.The estimates of dietary Ca requirements were 0.80 to 1.00%based on the best fitted broken-line or quadratic models(P<0.03)of the above serum and bone parameters,respectively.Conclusions:The results from the present study indicate that the Ca requirements would be about 0.60%to obtain the best growth rate,and 1.00%to meet all of the Ca metabolisms and bone development of broilers fed a conventional corn-soybean meal diet from 1 to 21 days of age.

Multiple Ionization Cross Sections of Ne and CO Induced by Very High-<i>q</i>Fast Projectiles (<i>q/v</i>>1)

In this paper, we extend our previous work of classical over barrier ionization (COBI) model to study the multiple ionization cross section of Ne and CO molecule collided by very high-q fast projectiles(q/v > 1). The model gives similar results to the independent-electron-approximation calculation and is in good agreement with experimental data. The very small computational time required makes it a good candidate for studying the multiple ionization of complex molecules under high linear energy transfers.

SC79 promotes efficient entry of GDNF liposomes into brain parenchyma to repair dopamine neurons through reversible regulation of tight junction proteins

Glial cell line-derived neurotrophic factor(GDNF),a disease-modifying drug for Parkinson’s disease(PD)is in Phase 2 clinical trials(EudraCT number:2011-003866-34),however it is administered by direct intrastriatal delivery via stereotaxy,which is accompanied with intracranial infection,brain tissue damage,and other complications.In addition,because of complex administration routes,clinical trials of GDNF have yielded contrary results,largely due to differences in dose and concentration brought by intracranial device.Herein,a small molecular agonist SC79 was screened to open blood-brain barrier(BBB)and promote GDNF liposomes to get into brain.SC79 reversibly reduces the expression of claudin-5,one of dominant tight junctions of BBB.Animal study showed SC79 promoted liposomes to enter into brain parenchyma 2.43 times more than that of the control.Motor deficits of PD mice receiving SC79 and brain-targeted GDNF liposomes were recovered by 36.70%and tyrosine hydroxylase positive neurons in striatum were restored by 39.90%.Our combination therapy effectively avoids the side effects such as secondary infection and uneven delivery caused by intracranial injection,improving patients’compliance and providing valuable research ideas for the clinic.

Erratum to:SC79 promotes efficient entry of GDNF liposomes into brain parenchyma to repair dopamine neurons through reversible regulation of tight junction proteins

Erratum to Nano Research 2023,16(2):2695-2705 https://doi.org/10.1007/s12274-022-4857-6 The article SC79 promotes efficient entry of GDNF liposomes into brain parenchyma to repair dopamine neurons through reversible regulation of tight junction proteins,written by Xiaomei Wu et al.,was erroneously originally published electronically on the publisher’s internet portal(currently SpringerLink)on 14 September 2022 with Fig.1(f)and a zeta potential value in Section 3.1.

Metabolic utilization of intravenously injected iron from different iron sources in target tissues of broiler chickens

No information is available regarding the utilization of iron (Fe) from different Fe sources at a targettissue level. To detect differences in Fe metabolic utilization among Fe sources, the effect of intravenouslyinjected Fe on growth performance, hematological indices, tissue Fe concentrations and Fe-containingenzyme activities and gene expressions of Fe-containing enzymes or protein in broilers was investigated.On d 22 post-hatching, a total of 432 male chickens were randomly allotted to 1 of 9 treatments ina completely randomized design. Chickens were injected with either a 0.9% (wt/vol) NaCl solution(control) or a 0.9% NaCl solution supplemented with Fe sulphate or 1 of 3 organic Fe sources. The 3organic Fe sources were Fe chelates with weak (Fe-MetW), moderate (Fe-ProtM) or extremely strong (Fe-ProtES) chelation strength. The 2 Fe dosages were calculated according to the Fe absorbabilities of 10%and 20% every 2 d for a duration of 20 d. Iron injection did not affect (P > 0.05) ADFI, ADG or FCR duringeither 1 to 10 d or 11 to 20 d after injections. Hematocrit and Fe concentrations in the liver and kidney ond 10 after Fe injections, and Fe concentrations in the liver or pancreas and ferritin heavy-chain (FTH1)protein expression level in the liver or spleen on d 20 after Fe injections increased (P≤0.05) as injectedFe dosages increased. When the injected Fe level was high at 20% Fe absorbability, the chickens injectedwith Fe-ProtES had lower (P < 0.001) liver or kidney Fe concentrations and spleen FTH1 protein levelsthan those injected with Fe-MetW or Fe-ProtM on d 20 after injections. And they had lower (P < 0.05)liver cytochrome C oxidase mRNA levels on d 20 after injections than those injected with Fe-MetW or Fesulphate. The results from this study indicate that intravenously injected Fe from Fe-ProtES was the least utilizable and functioned in the sensitive target tissue less effectively than Fe from Fe sulfate, Fe-MetW or Fe-ProtM.

Cell membrane coated-nanoparticles for cancer immunotherapy

Cancer immunotherapy can effectively inhibit cancer progression by activating the autoimmune system, with low toxicity and high effectiveness. Some of cancer immunotherapy had positive effects on clinical cancer treatment. However, cancer immunotherapy is still restricted by cancer heterogeneity, immune cell disability, tumor immunosuppressive microenvironment and systemic immune toxicity. Cell membrane-coated nanoparticles(CMCNs) inherit abundant source cell-relevant functions, including “self” markers, cross-talking with the immune system, biological targeting, and homing to specific regions. These enable them to possess preferred characteristics, including better biological compatibility, weak immunogenicity, immune escaping, a prolonged circulation, and tumor targeting.Therefore, they are applied to precisely deliver drugs and promote the effect of cancer immunotherapy.In the review, we summarize the latest researches of biomimetic CMCNs for cancer immunotherapy,outline the existing specific cancer immune therapies, explore the unique functions and molecular mechanisms of various cell membrane-coated nanoparticles, and analyze the challenges which CMCNs face in clinical translation.

Determination of optimal dietary selenium levels by full expression of selenoproteins in various tissues of broilers from 22 to 42 d of age

The current NRC dietary selenium(Se)requirement(0.15 mg/kg)of broilers from 22 to 42 d of age is primarily based on a previous study reported in 1986,which might not be applicable to modern classes of rapidly growing broilers.The present experiment was conducted to determine the optimal dietary Se level for meeting metabolic and functional Se requirements of broilers fed a corn-soybean meal diet from 22 to 42 d of age.A total of 336 Arbor Acres male broilers at 22 d old were randomly assigned to 1 of 6 treatments with 7 replicates and fed a basal corn-soybean meal diet(control,containing 0.014 mg Se/kg)and the basal diet supplemented with 0.10,0.20,0.30,0.40,or 0.50 mg Se/kg from Na_(2)SeO_(3) for 21 d.The results showed that the Se concentrations in plasma,liver,kidney,pancreas,breast and thigh muscles,the activity of glutathione peroxidase(GPX)in plasma,liver and kidney,the mRNA expression levels of Gpx4,selenoprotein(Seleno)h and Selenou in liver,Selenop and Selenoh in kidney,and the protein expression levels of GPX4 in the liver and kidney of broilers were affected(P<0.05)by supplemental Se level,and increased quadratically(P<0.05)with the increase of supplemental Se level.The estimates of optimal dietary Se levels were 0.10 to 0.49 mg/kg based on the fitted broken-line or asymptotic models(P<0.0001)of the above Se concentration indices,and 0.08 to 0.37 mg/kg based on the fitted brokenline,quadratic or asymptotic models(P<0.007)of the above selenoprotein expression indices.These results indicate that the optimal dietary Se levels would be 0.49 mg/kg to support the maximum Se concentrations and 0.37 mg/kg to support the full expression of selenoproteins in plasma and various tissues of broilers fed a corn-soybean meal diet from 22 to 42 d of age.