Genetically modified pigs with CD163 point mutation are resistant to HP-PRRSV infection

Porcine reproductive and respiratory syndrome(PRRS)is a globally prevalent contagious disease caused by the positive-strand RNA PRRS virus(PRRSV),resulting in substantial economic losses in the swine industry.Modifying the CD163 SRCR5 domain,either through deletion or substitution,can eff1ectively confer resistance to PRRSV infection in pigs.However,large fragment modifications in pigs inevitably raise concerns about potential adverse effects on growth performance.Reducing the impact of genetic modifications on normal physiological functions is a promising direction for developing PRRSV-resistant pigs.In the current study,we identified a specific functional amino acid in CD163 that influences PRRSV proliferation.Viral infection experiments conducted on Marc145 and PK-15CD163 cells illustrated that the mE535G or corresponding pE529G mutations markedly inhibited highly pathogenic PRRSV(HP-PRRSV)proliferation by preventing viral binding and entry.Furthermore,individual viral challenge tests revealed that pigs with the E529G mutation had viral loads two orders of magnitude lower than wild-type(WT)pigs,confirming effective resistance to HP-PRRSV.Examination of the physiological indicators and scavenger function of CD163 verified no significant differences between the WT and E529G pigs.These findings suggest that E529G pigs can be used for breeding PRRSV-resistant pigs,providing novel insights into controlling future PRRSV outbreaks.

Effect of Ti on microstructure and properties of electromagnetic stirred Al-18wt.%Mg_(2)Si alloy

By adding different amounts of Ti into the electromagnetic stirred Al-18wt.%Mg_(2)Si alloy,the effect of Ti element on the microstructure and mechanical properties of the alloy was studied.The experimental results show that the microstructure is refined after modification with Ti,which is related to the heterogeneous nucleation of TiAl_(3) particles on theα-Al matrix.With the increase of Ti content and holding time after stirring,the primary Mg_(2)Si phase is refined firstly and then coarsened,and correspondingly,the mechanical properties of the alloy show a trend of increasing at first and then decreasing.When the addition of Ti is 0.5wt.%and the holding time is about 20 min,the refinement effect of primary Mg_(2)Si phase is the most significant and the mechanical properties of the alloy are optimal.

Fiber Methane Gas Sensor and Its Application in Methane Outburst Prediction in Coal Mine

Fiber optic methane gas detecting system based on distributed feedback （DFB） laser wavelength scanning technique is demonstrated. Wavelength scan of methane absorption peak at 1665.9 nm is realized by saw tooth modulation of current which is injected to DFB laser. A reference methane gas cell is used to find the methane absorption peak around 1666 nm, and normalization is used to reduce the outside affection such as power drift, fiber loss. Concentration is got by arithmetic processing absorption coefficient of the methane gas. In-situ test is carried out in coal mine and long time precision of 0.05% is achieved. Some spot data of coal mine is introduced. By the system, methane outburst can be measured.

Dramatic Difference Between Cu_(20)H_(8)and Cu_(20)H_(9)Clusters in Catalysis

Sensitivity to structure and composition is very challenging to establish in nanocatalysis due to inadequate definition of structures that are very close in composition.We synthesized a pair of atomically precise copper clusters that are very close in composition,[Cu_(20)H_(9)(Tf-dpf)_(10)]·BF4(Cu_(20)H_(9))and[Cu_(20)H_(8)(Tf-dpf)_(10)]·(BF_(4))_(2)(Cu_(20)H_(8)),by using a pyridyl-functionalized flexible amidinate ligand,N,N′-di(5-trifluoromethyl-2-pyridyl)formamidinate.The one-hydride difference in their composition leads to significant variation in geometric and electronic structures and,consequently,distinctly different optical and catalytic properties.Cu_(20)H_(8)exhibits 25 times higher catalytic activity than Cu_(20)H_(9)(96.7%vs 3.7%in yield)in the selective hydrogenation of anα,β-unsaturated aldehyde(cinnamaldehyde)to saturated aldehyde(3-phenylpropanal).Electrospray ionization mass spectrometry combined with density functional theory calculations reveal that the greater ease of dissociation of one Tf-dpf ligand compared to Cu_(20)H_(8)is the key to its higher activity.This work demonstrates a clear case of structure and composition sensitivity in nanocatalysis and that one hydride,out of∼330 atoms in the nanoclusters,can make a huge difference in the catalytic activity.These insights will be useful in the design and synthesis of atomically precise nanocatalysts.