Application of Thermal Cycling Amplification Chip Method in the Detection of Respiratory Machine-Associated Pneumonia Pathogens.

Objective: Investigating the application effectiveness of using loop-mediated isothermal amplification (LAMP) on a microfluidic chip to detect the pathogens associated with ventilator-associated pneumonia (VAP). Methods: Eighty samples of bronchoalveolar lavage fluid from patients with ventilator-associated pneumonia (VAP) were collected at The First Hospital of Hebei Medical University from July 2022 to July 2023. The bacterial culture technique and the LAMP method were used to detect the nucleic acid of the pathogens in the patient samples. The positivity rates of bacterial culture and LAMP method in detecting VAP pathogens were analyzed. Results: A total of 80 specimens were examined, with 73 positive specimens detected using the LAMP method (positivity rate of 91.25%) and 60 positive specimens detected using bacterial culture (positivity rate of 75.00%). The LAMP method exhibited a higher number of positive detections compared to bacterial culture. Both methods showed a high level of concordance and were virtually identical in detecting methicillin-resistant Staphylococcus aureus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Enterobacter aerogenes, Haemophilus influenzae, and Streptococcus pneumoniae. Conclusion: The LAMP method demonstrates significantly improved performance in the detection of pathogens for VAP, with a higher pathogen positivity rate compared to bacterial culture. This method holds promising prospects for clinical application.

Polymeric Carbon Nitride with Chirality Inherited from Supramolecular Assemblies.

The facile synthesis of chiral materials is of paramount importance for various applications. Supramolecular preorganization of monomers for thermal polymerization has been proven as an effective tool to synthesize carbon and carbon nitride-based (CN) materials with ordered morphology and controlled properties. However, the transfer of an intrinsic chemical property, such as chirality from supramolecular assemblies to the final material after thermal condensation, was not shown. Here, we report the large-scale synthesis of chiral CN materials capable of enantioselective recognition. To achieve this, we designed supramolecular assemblies with a chiral center that remains intact at elevated temperatures. The optimized chiral CN demonstrates an enantiomeric preference of ca. 14 %; CN electrodes were also prepared and show stereoselective interactions with enantiomeric probes in electrochemical measurements. By adding chirality to the properties transferrable from monomers to the final product of a thermal polymerization, this study confirms the potential of using supramolecular precursors to produce carbon and CN materials and electrodes with designed chemical properties.

The Origin of Solvent Deprotonation in LiI-added Aprotic Electrolytes for Li-O2 Batteries.

LiI and LiBr have been employed as soluble redox mediators (RMs) in electrolytes to address the sluggish oxygen evolution reaction kinetics during charging in aprotic Li-O2 batteries. Compared to LiBr, LiI exhibits a redox potential closer to the theoretical one of discharge products, indicating a higher energy efficiency. However, the reason for the occurrence of solvent deprotonation in LiI-added electrolytes remains unclear. Here, by combining ab initio calculations and experimental validation, we find that it is the nucleophile I O 3 - ${{{\rm I}{\rm O}}_{3}^{-}}$ that triggers the solvent deprotonation and LiOH formation via nucleophilic attack, rather than the increased solvent acidity or the elongated C-H bond as previously suggested. As a comparison, the formation of B r O 3 - ${{{\rm B}{\rm r}{\rm O}}_{3}^{-}}$ in LiBr-added electrolytes is found to be thermodynamically unfavorable, explaining the absence of LiOH formation. These findings provide important insight into the solvent deprotonation and pave the way for the practical application of LiI RM in aprotic Li-O2 batteries.

Highly Efficient Polymeric Carbon Nitride Photoanode with Excellent Electron Diffusion Length and Hole Extraction Properties.

Polymeric carbon nitride (CN) has emerged as a promising semiconductor in photoanodes for photoelectrochemical cells (PECs) owing to its suitable electronic structure, tunable band gap, high stability, and low price. However, the poor electron diffusion within the CN layer and hole extraction to the solution still limit its applicability in PECs. Here, we report the fabrication of a CN photoanode with excellent electron diffusion length and remarkable hole extraction properties by careful design of its electronic interfaces. We combine complementary synthetic approaches to grow tightly packed CN layers forming a type-II heterojunction, which results in a CN photoanode with excellent charge separation, high electronic conductivity, and remarkable hole extraction efficiency. The optimized CN photoanode displays excellent PEC performance, reaching up to 270 µA cm-2 in a 0.1 M KOH solution at 1.23 V vs RHE, extremely low onset potential (∼0.0012 V), and long-term stability up to 18 h.

Deciphering the Ethylene Carbonate-Propylene Carbonate Mystery in Li-Ion Batteries.

As one of the landmark technologies, Li-ion batteries (LIBs) have reshaped our life in the 21stcentury, but molecular-level understanding about the mechanism underneath this young chemistry is still insufficient. Despite their deceptively simple appearances with just three active components (cathode and anode separated by electrolyte), the actual processes in LIBs involve complexities at all length-scales, from Li+ migration within electrode lattices or across crystalline boundaries and interfaces to the Li+ accommodation and dislocation at potentials far away from the thermodynamic equilibria of electrolytes. Among all, the interphases situated between electrodes and electrolytes remain the most elusive component in LIBs. Interphases form because no electrolyte component (salt anion, solvent molecules) could remain thermodynamically stable at the extreme potentials where electrodes in modern LIBs operate, and their chemical ingredients come from the sacrificial decompositions of electrolyte components. The presence of an interphase on electrodes ensures reversibility of Li+ intercalation chemistry in anode and cathode at extreme potentials and defines the cycle life, power and energy densities, and even safety of the eventual LIBs device. Despite such importance and numerous investigations dedicated in the past two decades, we still cannot explain why, nor predict whether, certain electrolyte solvents can form a protective interphase to support the reversible Li+ intercalation chemistries while others destroy the electrode structure. The most representative example is the long-standing "EC-PC Disparity" and the two interphasial extremities induced therefrom: differing by only one methyl substituent, ethylene carbonate (EC) forms almost ideal interphases on the graphitic anode, thus becoming the indispensable solvent in all LIBs manufactured today, while propylene carbonate (PC) does not form any protective interphase, leading to catastrophic exfoliation of the graphitic structure. With one after another hypotheses proposed but none satisfactorily rationalizing this disparity on the molecular level, this mystery has been puzzling the battery and electrochemistry community for decades. In this Account, we attempted to decipher this mystery by reviewing the key factors that govern the interaction between the graphitic structure and the solvated Li+ right before interphase formation. Combining DFT calculation and experiments, we identified the partial desolvation of the solvated Li+ at graphite edge sites as a critical step, in which the competitive solvation of Li+ by anion and solvent molecules dictates whether an electrolyte is destined to form a protective interphase. Applying this model to the knowledge of relative Li+ solvation energy and frontier molecular orbital energy gap, it becomes theoretically possible now to predict whether a new solvent or anion would form a complex with Li+ leading to desirable interphases. Such molecular-level understanding of interphasial processes provides guiding principles to the effort of tailor-designing new electrolyte systems for more aggressive battery chemistries beyond Li-ion.

A General Synthesis of Porous Carbon Nitride Films with Tunable Surface Area and Photophysical Properties.

Graphitic carbon nitride (g-CN) has emerged as a promising material for energy-related applications. However, exploitation of g-CN in practical devices is still limited owing to difficulties in fabricating g-CN films with adjustable properties and high surface area. A general and simple pathway is reported to grow highly porous and large-scale g-CN films with controllable chemical and photophysical properties on various substrates using the doctor blade technique. The growth of g-CN films, ascribed to the formation of a supramolecular paste, comprises g-CN monomers in ethylene glycol, which can be cast on different substrates. The g-CN composition, porosity, and optical properties can be tuned by the design of the supramolecular paste, which upon calcination results in a continuous porous g-CN network. The strength of the porous structure is demonstrated by high electrochemically active surface area, excellent dye adsorption and photoelectrochemical and photodegradation properties.

Influence of temperature on the capacitance of ionic liquid electrolytes on charged surfaces.

In this work using molecular dynamics simulations we examine the temperature dependence of the differential capacitance of room temperature ionic liquid electrolytes near electrified surfaces. For electrodes with atomically flat surfaces our simulations show very weak temperature dependence of the differential capacitance (DC) with a slight decrease of DC with increasing temperature. For atomically corrugated surfaces where the ion dimensions are comparable to the size of the surface corrugation patterns, the influence of temperature on DC is much more pronounced. At low temperatures the DC dependence on electrode potential shows large variations with well-defined maxima and minima. However, with increasing temperature these features are significantly flattened. Also for these corrugated surfaces an abnormal positive slope of DC vs. temperature is observed in the narrow range of relatively low voltages. Analysis of changes in the electric double layer structure as a function of temperature allowed us to propose a new mechanism explaining the observed trends in capacitance as a function of temperature and surface topography. The obtained simulation results are discussed in light of available experimental data and help to discriminate between contradictory experimentally observed trends in DC temperature dependence reported for ionic liquid based electrolytes in the literature.

Quantum chemistry study of the oxidation-induced stability and decomposition of propylene carbonate-containing complexes.

Oxidation-induced decomposition reactions of the representative complexes of propylene carbonate (PC)-based electrolytes were investigated using density functional theory (DFT) and a composite G4MP2 method. The cluster-continuum approach was used, where the oxidized PCn cluster was surrounded by the implicit solvent modeled via a polarized continuum model (PCM). The oxidative stability of the PCn (n = 2, 3, and 4) complexes was found to be around 5.4-5.5 V vs. Li(+)/Li, which is not only lower than the stability of an isolated PC but also lower than the stability of the PC-PF6(-), PC-BF4(-) or PC-ClO4(-) complexes surrounded by the implicit solvent. The oxidation-induced decomposition reactions were studied. The decomposition products of the oxidized PC2 contained CO2, acetone, propanal, propene, and carboxylic acid in agreement with the previous experimental studies.

Reference intervals of Cyfra21-1 and CEA in healthy adult Han Chinese population.

Objective: This study aimed to establish the reference intervals of Cyfra21-1 and CEA for the local screening populations using a chemiluminescence method. Methods: A total of 4845 healthy adults and 190 lung cancer patients were included from the First Hospital of Hebei Medical University. The levels of Cyfra21-1 and CEA were measured to establish the local reference intervals. Results: The upper limit reference intervals for Cyfra21-1 and CEA were determined as 3.19 ng/ml and 3.13 ng/ml, respectively. Notably, both Cyfra21-1 and CEA levels were found to be higher in males than in females. Additionally, both biomarkers showed an increasing trend with age.In terms of diagnostic efficacy, the receiver operating characteristic (ROC) curve areas for Cyfra21-1, CEA, and their combination in lung cancer were 0.86, 0.73, and 0.91, respectively. Conclusion: Our study revealed that the reference intervals of Cyfra21-1 and CEA in the local population differed from the established reference intervals. Furthermore, both biomarkers exhibited gender-dependent variations and demonstrated a positive correlation with age. Combining the two biomarkers showed potential for improving the diagnosis rate of lung cancer.

Insight into the Enforced Stability of the Solid Electrolyte Interphase on the Graphite Anode by Prelithiation.

Prelithiation in a graphite anode is widely considered as an effective strategy to compensate for the lithium loss due to the formation of the solid electrolyte interphase (SEI), thus improving the cycle life of lithium-ion batteries (LIBs). However, less attention has been paid to the difference of the SEI established by prelithiation from that resulting from the charging process. To address this issue, a prelithiated graphite anode is prepared by thermal contact and its performances are investigated by electrochemical measurements and spectral characterizations. It is found that the significantly improved initial coulombic efficiency (ICE) and cyclic stability of the graphite anode by prelitiation are attributed to the formation of LiF-rich SEI. Different from the charging process that favors decomposition of solvents and results in a SEI mainly consisting of organic and inorganic carbonates, prelithiation is beneficial for the reduction of LiPF6 and results in a LiF-rich SEI that presents high stability and robustness, enabling the graphite anode with significantly improved cyclic stability.

Developing extended visible light responsive polymeric carbon nitrides for photocatalytic and photoelectrocatalytic applications.

Polymeric carbon nitride (CN) has emerged as an attractive material for photocatalysis and photoelectronic devices. However, the synthesis of porous CNs with controlled structural and optical properties remains a challenge, and processable CN precursors are still highly sought after for fabricating homogenous CN layers strongly bound to a given substrate. Here, we report a general method to synthesize highly dispersed porous CN materials that show excellent photocatalytic activity for the hydrogen evolution reaction and good performance as photoanodes in photoelectrochemical cells (PEC): first, supramolecular assemblies of melem and melamine in ethylene glycol and water are prepared using a hydrothermal process. These precursors are then calcined to yield a water-dispersible CN photocatalyst that exhibits beneficial charge separation under illumination, extended visible-light response attributed to carbon doping, and a large number of free amine groups that act as preferential sites for a Pt cocatalyst. The optimized CN exhibits state-of-the-art HER rates up to 23.1 mmol h-1 g-1, with an AQE of 19.2% at 395 nm. This unique synthetic route enables the formation of a homogeneous precursor paste for substrate casting; consequently, the CN photoanode exhibits a low onset potential, a high photocurrent density and good stability after calcination.

B-/Si-containing electrolyte additive efficiently establish a stable interface for high-voltage LiCoO2 cathode and its synergistic effect on LiCoO2/graphite pouch cells.

An effective electrolyte additive, 3-(tert-Butyldimethylsilyoxy) phenylboronic acid (TBPB), is proposed to significantly improve the cycle stability of high voltage LiCoO2 (LCO) cathode. Experimental and computational results show that TBPB has a relatively higher oxidation activity than base electrolyte, and preferentially constructs a stable cathode electrolyte interphase (CEI) containing B-/Si- components on LCO surface. Theoretical calculation, XPS and NMR data show that TBPB-derived CEI layer contains B-F species and has the function of eliminating HF. The as-formed CEI effectively inhibits the detrimental side reactions from electrolyte decomposition and LCO surface structure reconstruction. The capacity retention of LCO/Li half-cell increases from 38.92% (base electrolyte) to 83.70% after 150 cycles at 1 C between 3.0 V and 4.5 V by adding 1% TBPB. Moreover, TBPB is also reduced prior to base electrolyte, forming an ionic conducting solid electrolyte interphase (SEI) on graphite surface. Benefiting from the synergistic effect between CEI layer on LCO cathode and SEI layer on graphite anode to effectively decrease the electrolyte decomposition, the capacity retention of commercial LCO/graphite pouch cell with 1% TBPB increases from 10.44% to 76.13% after 400 cycles at 1 C between 3.0 V and 4.5 V. This work demonstrates that TBPB can act as an effective film-forming additive for high energy density LCO cathode at high voltage, and provides novel insights for its commercial application from the aspect of synergistically interfacial stability.

A biocompatible electrolyte enables highly reversible Zn anode for zinc ion battery.

Progress towards the integration of technology into living organisms requires power devices that are biocompatible and mechanically flexible. Aqueous zinc ion batteries that use hydrogel biomaterials as electrolytes have emerged as a potential solution that operates within biological constraints; however, most of these batteries feature inferior electrochemical properties. Here, we propose a biocompatible hydrogel electrolyte by utilising hyaluronic acid, which contains ample hydrophilic functional groups. The gel-based electrolyte offers excellent anti-corrosion ability for zinc anodes and regulates zinc nucleation/growth. Also, the gel electrolyte provides high battery performance, including a 99.71% Coulombic efficiency, over 5500 hours of long-term stability, improved cycle life of 250 hours under a high zinc utilization rate of 80%, and high biocompatibility. Importantly, the Zn//LiMn2O4 pouch cell exhibits 82% capacity retention after 1000 cycles at 3 C. This work presents a promising gel chemistry that controls zinc behaviour, offering great potential in biocompatible energy-related applications and beyond.

Breaking solvation dominance of ethylene carbonate via molecular charge engineering enables lower temperature battery.

Low temperatures severely impair the performance of lithium-ion batteries, which demand powerful electrolytes with wide liquidity ranges, facilitated ion diffusion, and lower desolvation energy. The keys lie in establishing mild interactions between Li+ and solvent molecules internally, which are hard to achieve in commercial ethylene-carbonate based electrolytes. Herein, we tailor the solvation structure with low-ε solvent-dominated coordination, and unlock ethylene-carbonate via electronegativity regulation of carbonyl oxygen. The modified electrolyte exhibits high ion conductivity (1.46 mS·cm-1) at -90 °C, and remains liquid at -110 °C. Consequently, 4.5 V graphite-based pouch cells achieve ~98% capacity over 200 cycles at -10 °C without lithium dendrite. These cells also retain ~60% of their room-temperature discharge capacity at -70 °C, and miraculously retain discharge functionality even at ~-100 °C after being fully charged at 25 °C. This strategy of disrupting solvation dominance of ethylene-carbonate through molecular charge engineering, opens new avenues for advanced electrolyte design.

Oxidation induced decomposition of ethylene carbonate from DFT calculations--importance of explicitly treating surrounding solvent.

The oxidation induced reactions of the common lithium battery electrolyte solvent ethylene carbonate (EC) have been investigated for EC(2) using density functional theory and for selected reaction paths using Møller-Plesset perturbation theory (MP4). The importance of explicitly treating at least one solvent molecule interacting with EC during oxidation (removal of an electron) on the EC oxidation potential and decomposition reactions was shown by comparing oxidation of EC and EC(2). Accuracy of DFT results was evaluated by comparing with MP4 and G4 values for oxidation of EC. The polarized continuum model (PCM) was used to implicitly include the rest of the surrounding solvent. The oxidation potentials of EC(2) and EC(4) were found to be significantly lower than the intrinsic oxidation potential of an isolated EC and also lower than the oxidation potential of EC-BF(4)(-). The exothermic proton abstraction from the ethylene group of EC by the carbonyl group of another EC was responsible for the decreased oxidative stability of EC(2) and EC(4) compared to EC. The most exothermic path with the smallest barrier for EC(2) oxidation yielded CO(2) and an ethanol radical cation. The reaction paths with the higher barrier yielded oligo(ethylene carbonate) suggesting a pathway for the experimentally observed poly(ethylene carbonate) formation of EC-based electrolytes at cathode surfaces.

Construction of Low-Impedance and High-Passivated Interphase for Nickel-Rich Cathode by Low-Cost Boron-Containing Electrolyte Additive.

The nickel-rich cathode LiNi0.8 Co0.1 Mn0.1 O2 (NCM811) possesses the advantages of high reversible specific capacity and low cost, thus regarded as a promising cathode material for lithium-ion batteries (LIBs). However, the capacity of the NCM811 decays rapidly at high voltage due to the extremely unstable electrode/electrolyte interphase. The discharge capability at low temperature is also impaired because of the increasing interfacial impedance. Herein, a low-cost film-forming electrolyte additive with multi-function, phenylboronic acid (PBA), was employed to modify the interphasial properties of the NCM811 cathode. Theoretical calculation and experimental results showed that PBA constructed a highly conductive and steady cathode electrolyte interphase (CEI) film through preferential oxidation decomposition, which greatly improved the interfacial properties of the NCM811 cathode at room (25 °C) and low temperature (-10 °C). Specifically, the capacity retention of NCM811/Li cell was increased from 68 % to 87 % after 200 cycles with PBA additive. Moreover, the NCM811/Li cell with PBA additive delivered higher discharge capacity under -10 °C at 0.5 C (173.7 mAh g-1 vs. 111.1 mAh g-1 ). Based on the improvement of NCM811 interphasial properties by additive PBA, the capacity retention of NCM811/graphite full-cell was enhanced from 49 % to 65 % after 200 cycles.

A diagnostic test of real-time PCR detection in the diagnosis of clinical bloodstream infection.

BACKGROUND: Blood culture remains the standard for diagnosing bloodstream infections, but it is difficult to identify bacteria directly and timeliness. The real-time polymerase chain reaction (PCR) has the potential to fill this diagnostic gap. This study intends to explore the sensitivity and specificity of PCR in detecting bloodstream infection pathogens and to compare it with routine blood culture to explore its clinical application value. METHODS: A total of 126 patients with bloodstream infections collected from various clinical departments of The First Hospital of Hebei Medical University. The patient's sample was divided into two parts. The one for multiplex PCR detection was performed using the Pathogeno Elite Multiplex PCR kit. Another blood culture was a fully automatic blood culture system from Autobio company. RESULTS: Among the 126 patients, a total of 17 pathogens were detected by PCR and blood culture both methods. PCR detected a total of 43 positive samples and 83 negative samples. Five samples were positive with blood culture, and 81 were negative. The negative predictive value of PCR was 0.98, with a sensitivity of 0.71 and a specificity of 0.68. A total of 38 specimens were positive for PCR but negative for blood culture, and 2 samples were positive for blood culture but negative for PCR. The top 5 pathogens with PCR detection were Epstein-Barr virus (27 cases), Human herpes virus 5 (9 cases), Klebsiella pneumoniae (5 cases), Staphylococcus (5 cases), and Stenotrophomonas maltophilia (4 cases). CONCLUSIONS: PCR detection can rapidly identify more pathogens and even multi-pathogen infections. Therefore, PCR testing may improve pathogen detection in patients with suspected bloodstream infections, enabling targeted treatment of patients.

Insight into the Contribution of Nitriles as Electrolyte Additives to the Improved Performances of the LiCoO2 Cathode.

Nitriles have been successfully used as electrolyte additives for performance improvement of commercialized lithium-ion batteries based on the LiCoO2 cathode, but the underlying mechanism is unclear. In this work, we present an insight into the contribution of nitriles via experimental and theoretical investigations, taking for example succinonitrile. It is found that succinonitrile can be oxidized together with PF6- preferentially on LiCoO2 compared to the solvents in the electrolyte, making it possible to avoid the formation of hydrogen fluoride from the electrolyte oxidation decomposition, which is detrimental to the LiCoO2 cathode. Additionally, inorganic LiF and -NH group-containing polymers are formed from the preferential oxidation of succinonitrile, constructing a protective interphase on LiCoO2, which suppresses electrolyte oxidation decomposition and prevents LiCoO2 from structural deterioration. Consequently, the LiCoO2 cathode presents excellent stability under cycling and storing at high voltages.

Density functional theory study of the role of anions on the oxidative decomposition reaction of propylene carbonate.

The oxidative decomposition mechanism of the lithium battery electrolyte solvent propylene carbonate (PC) with and without PF(6)(-) and ClO(4)(-) anions has been investigated using the density functional theory at the B3LYP/6-311++G(d) level. Calculations were performed in the gas phase (dielectric constant ε = 1) and employing the polarized continuum model with a dielectric constant ε = 20.5 to implicitly account for solvent effects. It has been found that the presence of PF(6)(-) and ClO(4)(-) anions significantly reduces PC oxidation stability, stabilizes the PC-anion oxidation decomposition products, and changes the order of the oxidation decomposition paths. The primary oxidative decomposition products of PC-PF(6)(-) and PC-ClO(4)(-) were CO(2) and acetone radical. Formation of HF and PF(5) was observed upon the initial step of PC-PF(6)(-) oxidation while HClO(4) formed during initial oxidation of PC-ClO(4)(-). The products from the less likely reaction paths included propanal, a polymer with fluorine and fluoro-alkanols for PC-PF(6)(-) decomposition, while acetic acid, carboxylic acid anhydrides, and Cl(-) were found among the decomposition products of PC-ClO(4)(-). The decomposition pathways with the lowest barrier for the oxidized PC-PF(6)(-) and PC-ClO(4)(-) complexes did not result in the incorporation of the fluorine from PF(6)(-) or ClO(4)(-) into the most probable reaction products despite anions and HF being involved in the decomposition mechanism; however, the pathway with the second lowest barrier for the PC-PF(6)(-) oxidative ring-opening resulted in a formation of fluoro-organic compounds, suggesting that these toxic compounds could form at elevated temperatures under oxidizing conditions.

Theoretic calculation for understanding the oxidation process of 1,4-dimethoxybenzene-based compounds as redox shuttles for overcharge protection of lithium ion batteries.

The effect of substituents on the oxidation potential for the one-electron reaction of 1,4-dimethoxybenzene was understood with a theoretical calculation based on density functional theory (DFT) at the level of B3LYP/6-311+G(d). It is found that the oxidation potential for the one-electron reaction of 1,4-dimethoxybenzene is 4.13 V (vs Li/Li(+)) and can be changed from 3.8 to 5.9 V (vs Li/Li(+)) by substituting electron-donating or electron-withdrawing groups for the hydrogen atoms on the aromatic ring. These potentials are in the range of the limited potentials for the lithium ion batteries using different cathode materials, and thus the substituted compounds can be selected as the redox shuttles for the overcharge prevention of these batteries. The oxidation potential of 1,4-dimethoxybenzene decreases when the hydrogen atoms are replaced with electron-donating groups but increases when replaced with electron-withdrawing groups. The further oxidation of these substituted compounds was also analyzed on the basis of the theoretic calculation.