LygA retention on the surface of Listeria monocytogenes via its interaction with wall teichoic acid modulates bacterial homeostasis and virulence.

Wall teichoic acid (WTA) is the abundant cell wall-associated glycopolymer in Gram-positive bacteria, playing crucial roles in surface proteins retention, bacterial homeostasis, and virulence. The WTA glycosylation of Listeria monocytogenes is essential for surface anchoring of virulence factors, whereas the nature and function of the noncovalent interactions between cell wall-associated proteins and WTA are less unknown. In this study, we found that galactosylated WTA (Gal-WTA) of serovar (SV) 4h L. monocytogenes plays a key role in modulating the novel glycine-tryptophan (GW) domain-containing autolysin protein LygA through direct interactions. Gal-deficient WTA of Lm XYSN (ΔgalT) showed a dramatic reduction of LygA on the cell surface. We demonstrated that LygA binds to Gal-WTA through the GW domains, and the binding affinity is associated with the number of GW motifs. Moreover, we confirmed the direct Gal-dependent binding of the GW protein Auto from the type I WTA strain, which has no interaction with rhamnosylated WTA, indicating that the complexity of both WTA and GW proteins affect the coordination patterns. Importantly, we revealed the crucial roles of LygA in facilitating bacterial homeostasis as well as crossing the intestinal and blood-brain barriers. Altogether, our findings suggest that both the glycosylation patterns of WTA and a fixed numbers of GW domains are closely associated with the retention of LygA on the cell surface, which promotes the pathogenesis of L. monocytogenes within the host.

Organo-photoredox catalyzed gem-difluoroallylation of ketone-derived dihydroquinazolinones via C(sp3)-C bond and C(sp3)-F bond cleavage.

An organo-photoredox catalyzed gem-difluoroallylation of both acyclic and cyclic ketone derivatives with α-trifluoromethyl alkenes has been demonstrated, thus giving access to a diverse set of gem-difluoroalkenes in moderate to high yields. Pro-aromatic dihydroquinazolinones can be either pre-formed or in situ generated for ketone activation. This reaction is characterized by readily available starting materials, mild reaction conditions, and broad substrate scope. The feasibility of this reaction has been highlighted by the late-stage modification of several natural products and drug-like molecules as well as the in vitro antifungal activity.

Archaeal communities change responding to anthropogenic and natural treatments of freeze-thawed soils.

The coverage of accumulated snow plays a significant role in inducing changes in both microbial activity and environmental factors within freeze-thaw soil systems. This study aimed to analyze the impact of snow cover on the dynamics of archeal communities in freeze-thaw soil. Furthermore, it seeks to investigate the role of fertilization in freeze-thaw soil. Four treatments were established based on snow cover and fertilization:No snow and no fertilizer (CK-N), snow cover without fertilizer (X-N), fertilizer without snow cover (T-N), and both fertilizer and snow cover (T-X). The research findings indicated that after snow cover treatment, the carbon, nitrogen, and phosphorus content in freeze-thaw soil exhibit periodic fluctuations. Snow covered effectively altered the community composition of bacteria and archaea in the soil, with a greater impact on archaeal communities than on bacterial communities. Snow covered improves the stability of archaeal communities in freeze-thaw soil. Additionally, the arrival of snow also enhanced the correlation between archaea and environmental factors, with the key archaeal phyla involved being Nanoarchaeota and Crenarchaeota. Further research showed that the application of organic fertilizers also had some impact on freeze-thaw soil, but this impact was smaller compared to snow cover. In summary, the arrival of snow could alter the archaeal community and protect nutrient elements in freeze-thaw soil, reducing their loss, and its effect is more pronounced compared to the application of organic fertilizers.

Co-composting sugar-containing waste with chicken manure-A new approach to carbon sequestration.

Improving resource use is a pressing research issue because of the huge potential organic waste market. Composting is a recycling technique, treatment to achieve the dual effect of resource recovery and zero waste. Waste composition varies: for example, chicken manure is rich in protein, straw contains wood fibres, fruit and vegetables contain sugar, and food waste contains starch. When considering combining waste streams for composting, it is important to ask if this approach can reduce overall composting costs while achieving a more concentrated result. Chicken manure, in particular, presents a unique challenge. This is due to its high protein content. The lack of precursor sugars for glucosamine condensation in chicken manure results in lower humus content in the final compost than other composting methods. To address this, we conducted experiments to investigate whether adding sugary fruits and vegetables to a chicken manure composting system would improve compost quality. To improve experimental results, we used sucrose and maltose instead of fruit and vegetable waste. Sugars added to chicken manure composting resulted in a significant increase in humic substance (HS) content, with improvements of 9.0% and 17.4%, respectively, compared to the control. Sucrose and maltose have a similar effect on the formation of humic substances. These results demonstrate the feasibility of composting fruit and vegetable waste with chicken manure, providing a theoretical basis for future composting experiments.

InAs/GaAs quantum-dot lasers grown on on-axis Si (001) without dislocation filter layers.

InAs/GaAs quantum dot (QD) laser monolithically grown on silicon is one of the potential approaches to realizing silicon-based light sources. However, the mismatch between GaAs and Si generates a high density of threading dislocations (TDs) and antiphase boundaries (APBs), which trap carriers and adversely affect device performance. In this paper, we present a simple method to reduce the threading dislocation density (TDD) merely through GaAs buffer, eliminating the intricate dislocation filter layers (DFLs) as well as any intermediate buffer layers whose compositions are different from the target GaAs. An APB-free epitaxial 2.5 µm GaAs film was grown on exact Si (001) by metalorganic chemical vapor deposition (MOCVD) with a TDD of 9.4 × 106 cm-2. InAs/GaAs QDs with a density of 5.2 × 1010 cm-2 were grown on this GaAs/Si (001) virtual substrate by molecular beam epitaxy (MBE) system. The fabricated QD laser has achieved a single facet room temperature continuous-wave output power of 138 mW with a threshold current density of 397 A/cm2 and a lasing wavelength of 1306 nm. In this work, we propose a simplified method to fabricate high-power QD lasers, which is expected to promote the application of photonic integrated circuits.

Serial dependence in orientation judgments at the time of saccades.

We actively seek information from the environment through saccadic eye movements, necessitating continual integration of presaccadic and postsaccadic signals, which are displaced on the retina by each saccade. We tested whether trans-saccadic integration may be related to serial dependence (a measure of how perceptual history influences current perception) by measuring how viewing a presaccadic stimulus affects the perceived orientation of a subsequent test stimulus presented around the time of a saccade. Participants reproduced the position, and orientation of a test stimulus presented around a 16° saccade. The reproduced position was mislocalized toward the saccadic target, agreeing with previous work. The reproduced orientation was attracted toward the prior stimulus and regressed to the mean orientation. These results suggest that both short- and long-term past information affects trans-saccadic perception, most strongly when the test stimulus is presented perisaccadically. This study unites the fields of serial dependence and trans-saccadic perception, leading to potential new insights of how information is transferred and accumulated across saccades.

Effectiveness of flipped classroom in pharmacy education - a meta-analysis.

BACKGROUND: Flipped classroom, blended with online and offline learning, was regarded as an effective learning approach in pharmacy education. This meta-analysis was to comprehensively compare the effectiveness of flipped classroom and traditional lecture-based approaches, attempting to generate a unified and firm conclusion of the effectiveness of flipped classroom in pharmacy education. METHODS: Data were collected from 7 databases, involving Cochrane Library, PubMed, Embase, ScienceDirect, Web of Science, China National Knowledge Infrastructure (CNKI), and Chinese Biomedical Literature Service System (SinoMed). The studies were included if they included objective evaluation of students' performance between groups of flipped classroom and traditional approaches. The standardized mean difference (SMD) with a corresponding 95% confidence interval (95% CI) was used as the outcomes for data pooling. RESULTS: A total of 22 studies (28 comparing groups) with 4379 participants were included in the meta-analysis. The risk of bias was relatively high. Results of the analysis revealed that flipped classroom presented significant advantages over traditional approaches in student performance improvement, with no evidence of publication bias. Through subgroup analysis, it showed better outcomes for flipped classrooms over traditional lectures for the other subgroups, including different performance, degree programs. CONCLUSIONS: Current evidence reveals that the flipped classroom approach in pharmacy education yields a statistical improvement in student learning compared with traditional methods. In the future, instructors should introduce more online technology into classroom and construct an interactive learning environment.

Photoswitchable Oxidopyrylium Ylide for Photoclick Reaction with High Spatiotemporal Precision: A Dynamic Switching Strategy to Compensate for Molecular Diffusion.

We describe a novel type of photoclick reaction between 2,3-diaryl indenone epoxide (DIO) and ring-strained dipolarophiles, in which DIO serves as a P-type photoswitch to produce mesoionic oxidopyrylium ylide (PY) to initiate an ultra-fast [5+2] cycloaddition (k2hν =1.9×105  M-1 s-1 ). The photoisomerization between DIO and PY can be tightly controlled by either 365 or 520 nm photo-stimulation, which allows reversion or regeneration of the reactive PY dipole on demand. Thus, this reversible photoactivation was exploited to increase the chemoselectivity of the [5+2] cycloaddition in complex environments via temporal dual-λ stimulation sequences and to recycle the DIO reagent for batch-wise protein conjugation. A dynamic photoswitching strategy is also proposed to compensate for molecular diffusion of PY in aqueous solution, enhancing the spatial resolution of lithographic surface decoration and bioorthogonal labeling on living cells via a spatiotemporal dual-λ photo-modulation.

Rationally Regulating the Mechanical Performance of Porous PDMS Coatings for the Enhanced Icephobicity toward Large-Scale Ice.

Ice accumulation on various surfaces in low-temperature and high-humidity environments is still a major challenge for several engineering applications. Herein, we fabricated a kind of PDMS coating with the introduction of porous structures under the surface by a two-step curing and phase separation method. The coatings with no further surface modification showed good hydrophobicity and icephobicity, and the typical ice adhesion strength was down to 40 kPa with a water contact angle of 116.5°. More than that, the porous PDMS coatings showed extraordinary icephobicity, especially toward large-scale ice (>10 cm2). In this case, the large-scale ice layer can be rapidly removed under a small external deicing force in a form of interface crack propagation rather than whole direct fracture. It was confirmed that by regulating the pore size and porosity of PDMS coatings properly, the stiffness mismatch between coatings and ice can be controlled to induce the initiation of interfacial cracks. On this basis, under the condition of a large-scale icing area, a small external deicing force can cause an increased surface stress concentration, and the formed interface cracks can propagate quickly, resulting in the ice layer falling off easily. In addition, under the influence of the size effect, ice can be removed without an additional force, and the minimum external force (per unit width) can be only 60 N/cm. This paper proposes that prefabricating a large number of microcracks at the interface can significantly weaken the bonding between ice and coatings, that is, reduce the fracture toughness. The new coatings have a remarkable effect toward large-scale icing.

Vision improvement in indirect traumatic optic neuropathy treated by endoscopic transnasal optic canal decompression.

BACKGROUND: Indirect Traumatic optic neuropathy (ITON) is a severe disease characterized by a sudden decline of visual function after craniofacial injury. However, the best treatment for ITON is unknown. Endoscopic transnasal optic canal decompression (ETOCD) has gradually been used for ITON treatment worldwide in recent years. OBJECTIVE: To assess the effect of ETOCD on visual acuity in patients with ITON and identify factors that affect prognosis. METHODS: In this study, clinical characteristics of 44 ITON patients who underwent ETOCD in Qilu Hospital of Shandong University were retrospectively analyzed. Factors affecting prognosis were also evaluated. RESULTS: ETOCD treatment improved the vision of 20 (45.5%) patients with no patient suffering from vision deterioration. The mean value of visual acuity (VA) scores improved from 1.57 to 2.39 (P < 0.001). Patients with residual vision had a better VA improvement percent than those without light perception (66.67% versus 34.48%, χ2 = 4.13, P = 0.042). Although shorter duration before ETOCD was associated with better improvement score in ITON patients (r = -0.30, P = 0.044), optic canal fracture (OCF) and optic nerve sheath incision did not affect the prognosis of these patients. Five ITON patients with cerebrospinal fluid rhinorrhea were treated with free nasal mucosal flap during the surgery, and no other severe surgical complication occurred. CONCLUSIONS: ETOCD can effectively and safely improve the vision of ITON patients, patients with residual vision and those treated earlier may benefit more from this surgery.

Dibenzo[b,f][1,4,5]chalcogenadiazepine Photoswitches: Conversion of Excitation Energy into Ring Strain.

Tetra-ortho-substituted, heteroaryl and cyclic azobenzenes have emerged as three key strategies on morphology design of photoswitch to diversify controllability. Cyclic azobenzene is of particular utilization in photo-energy conversion due to rigid and ring-strain structure. Despite the well-recognized diazocine, the photo-switching properties of seven-membered cyclic azobenzenes (diazepines) have yet been exploited. Herein, we report a family of dibenzo[b,f][1,4,5]chalcogenadiazepines (DBChDs) and their T-type photo-switching nature with tunable relaxation rate. Based on experiments together with DFT calculations, we found that an unsymmetric 2-bithiophenyl-dibenzo[b,f][1,4,5]thiadiazepine exhibited an efficient response to 445 nm laser stimulation (quantum efficiency, ΦZ→E =0.71) with millisecond relaxation half-life (t1/2 =40 ms). Photo-energy transduction efficiency was also exceptionally high with 29.1 % converted into ring-strain energy mainly loaded on azo π-bond.

Recycling diagnostic MRI for empowering brain morphometric research - Critical & practical assessment on learning-based image super-resolution.

Preliminary studies have shown the feasibility of deep learning (DL)-based super-resolution (SR) technique for reconstructing thick-slice/gap diagnostic MR images into high-resolution isotropic data, which would be of great significance for brain research field if the vast amount of diagnostic MRI data could be successively put into brain morphometric study. However, less evidence has addressed the practicability of the strategy, because lack of a large-sample available real data for constructing DL model. In this work, we employed a large cohort (n = 2052) of peculiar data with both low through-plane resolution diagnostic and high-resolution isotropic brain MR images from identical subjects. By leveraging a series of SR approaches, including a proposed novel DL algorithm of Structure Constrained Super Resolution Network (SCSRN), the diagnostic images were transformed to high-resolution isotropic data to meet the criteria of brain research in voxel-based and surface-based morphometric analyses. We comprehensively assessed image quality and the practicability of the reconstructed data in a variety of morphometric analysis scenarios. We further compared the performance of SR approaches to the ground truth high-resolution isotropic data. The results showed (i) DL-based SR algorithms generally improve the quality of diagnostic images and render morphometric analysis more accurate, especially, with the most superior performance of the novel approach of SCSRN. (ii) Accuracies vary across brain structures and methods, and (iii) performance increases were higher for voxel than for surface based approaches. This study supports that DL-based image super-resolution potentially recycle huge amount of routine diagnostic brain MRI deposited in sleeping state, and turning them into useful data for neurometric research.

Cortico-striato-thalamo-cerebellar networks of structural covariance underlying different epilepsy syndromes associated with generalized tonic-clonic seizures.

Generalized tonic-clonic seizures (GTCS) are the severest and most remarkable clinical expressions of human epilepsy. Cortical, subcortical, and cerebellar structures, organized with different network patterns, underlying the pathophysiological substrates of genetic associated epilepsy with GTCS (GE-GTCS) and focal epilepsy associated with focal to bilateral tonic-clonic seizure (FE-FBTS). Structural covariance analysis can delineate the features of epilepsy network related with long-term effects from seizure. Morphometric MRI data of 111 patients with GE-GTCS, 111 patients with FE-FBTS and 111 healthy controls were studied. Cortico-striato-thalao-cerebellar networks of structural covariance within the gray matter were constructed using a Winner-take-all strategy with five cortical parcellations. Comparisons of structural covariance networks were conducted using permutation tests, and module effects of disease duration on networks were conducted using GLM model. Both patient groups showed increased connectivity of structural covariance relative to controls, mainly within the striatum and thalamus, and mostly correlated with the frontal, motor, and somatosensory cortices. Connectivity changes increased as a function of epilepsy durations. FE-FBTS showed more intensive and extensive gray matter changes with volumetric loss and connectivity increment than GE-GTCS. Our findings implicated cortico-striato-thalamo-cerebellar network changes at a large temporal scale in GTCS, with FE-FBTS showing more severe network disruption. The study contributed novel imaging evidence for understanding the different epilepsy syndromes associated with generalized seizures.

Droplet Directional Movement on the Homogeneously Structured Superhydrophobic Surface with the Gradient Non-Wettability.

The surface with the gradient non-wettability intensely appeals to researchers because of its academic significance and applications for directional droplet movement. Herein, we developed a homogeneous structure superhydrophobic surface with the gradient non-wettability by a combination strategy of chemical etching and vapor diffusion modification. As a consequence, the as-prepared surface exhibits a remarkable gradient characteristic of water repellency, and the water contact angle is mainly located within the range of 162 ± 0.5 to 149 ± 0.4°. Meanwhile, the sliding angle also exhibits a corresponding change from 3 to 11°. On this basis, the gradient characteristic of non-wettability induces the distinguishing droplet adhesion on the surface, that is, from 19 µN for the most hydrophobic end to 57 µN for the opposite one. Because of the difference of the water adhesion force, droplets on the as-prepared surface can well roll alongside a specific direction (i.e., gradient direction of non-wettability). In terms of dynamic impact droplets, they can rapidly rebound off the sample surface with the short contact time of 12.8 ms, and the finally fallen droplets mainly deviate toward weaker regions because of water repellency. To analyze this phenomenon, it is found that the asymmetric mechanic behavior is mainly caused by the unbalanced retraction force between the both ends of the impact droplet. This work provides a novel strategy to construct the homogeneous structure superhydrophobic surface with the gradient non-wettability for the applications in the droplet movement control or transport.

A new format of perceptual learning based on evidence abstraction from multiple stimuli.

Perceptual learning, which improves stimulus discrimination, typically results from training with a single stimulus condition. Two major learning mechanisms, early cortical neural plasticity and response reweighting, have been proposed. Here we report a new format of perceptual learning that by design may have bypassed these mechanisms. Instead, it is more likely based on abstracted stimulus evidence from multiple stimulus conditions. Specifically, we had observers practice orientation discrimination with Gabors or symmetric dot patterns at up to 47 random or rotating location × orientation conditions. Although each condition received sparse trials (12 trials/session), the practice produced significant orientation learning. Learning also transferred to a Gabor at a single untrained condition with two- to three-times lower orientation thresholds. Moreover, practicing a single stimulus condition with matched trial frequency (12 trials/session) failed to produce significant learning. These results suggest that learning with multiple stimulus conditions may not come from early cortical plasticity or response reweighting with each particular condition. Rather, it may materialize through a new format of perceptual learning, in which orientation evidence invariant to particular orientations and locations is first abstracted from multiple stimulus conditions and then reweighted by later learning mechanisms. The coarse-to-fine transfer of orientation learning from multiple Gabors or symmetric dot patterns to a single Gabor also suggest the involvement of orientation concept learning by the learning mechanisms.

Diversity in the Mechanisms of Humin Formation during Composting with Different Materials.

Humins (HMs) play a very important role in various environmental processes and are crucial for regulating global carbon and nitrogen cycles in various ecosystems. Composting is a controlled decomposition process accompanied by the stabilization of organic solid waste materials. During composting, active fractions of organic substances can be transformed into HMs containing stable and complex macromolecules. However, the structural heterogeneity and formation mechanisms of HMs during composting with various substrates have not been clarified. Here, the structure and composition of HMs extracted from livestock manure (LM) and straw (SW) during composting were investigated by excitation-emission matrices spectroscopy and Fourier transform infrared spectroscopy. The results showed that the stability and humification of LM-HM were lower than that of SW-HM. The parallel factor analysis components of the HM in LM composting contained the same fluorescent unit, and the intermediate of cellulose degradation affected the structure of the HM from SW composting. Structural equation modeling demonstrated that low-molecular-weight compounds were key factors in humification. On the basis of the structure and key factors impacting HM, we constructed two mechanisms for the formation of HM from different composting processes. The LM-HMs from different humification processes have multiple identical fluorescent structural units, and the high humification of SW is affected by its polysaccharide constituents, which contains a fluorescent component in their skeleton, providing a basis for studying HM in composting.

Statistically understanding the roles of nanostructure features in interfacial ice nucleation for enhancing icing delay performance.

Freezing is a spontaneous phase transformation process, which is mainly governed by heterogeneous ice nucleation. This work aims at the discussion of the roles of nanostructure geometrical features in interfacial ice nucleation. Two kinds of superhydrophobic nanostructures with sealed layered porous and open cone features were designed and fabricated by means of wet-chemical processing methods. Both the resultant surfaces exhibited a larger extent of improvement of non-wettability, especially in the aspect of droplet movement. Comparing with the sealed layered nanoporous structures, the open nanocone structures only induced a sliding angle of 1°. During the freezing process, the solid-liquid contact type highly determined the macroscopic freezing process, and resulted in a difference of icing delay time of ∼170 s (and freezing temperature of ∼3.7 °C) between both superhydrophobic nanostructures. Also, the precooling time, the period before the moment of a droplet instantaneously becoming turbid, occupied a dominant role (∼90%) in the entire freezing time. The ice nucleation behavior was analyzed in detail according to the statistical results of 500 cycles of freezing temperatures, demonstrating that the ice nucleation probability of nanocone structures is less than that of layered nanoporous structures. This is in line with the ice nucleation temperatures of both as-prepared superhydrophobic nanostructures. As a consequence, there was a greater distinction in the ice nucleation rate, especially in the solid-liquid interface nucleation rate, by two orders of magnitude.

Overexpression of microRNA408 enhances photosynthesis, growth, and seed yield in diverse plants.

The ability of a plant to produce grain, fruit, or forage depends ultimately on photosynthesis. There have been few attempts, however, to study microRNAs, which are a class of endogenous small RNAs post-transcriptionally programming gene expression, in relation to photosynthetic traits. We focused on miR408, one of the most conserved plant miRNAs, and overexpressed it in parallel in Arabidopsis, tobacco, and rice. The transgenic plants all exhibited increased copper content in the chloroplast, elevated abundance of plastocyanin, and an induction of photosynthetic genes. By means of gas exchange and optical spectroscopy analyses, we showed that higher expression of miR408 leads to enhanced photosynthesis through improving efficiency of irradiation utilization and the capacity for carbon dioxide fixation. Consequently, miR408 hyper-accumulating plants exhibited higher rate of vegetative growth. An enlargement of seed size was also observed in all three species overproducing miR408. Moreover, we conducted a 2-year-two-location field trial and observed miR408 overexpression in rice significantly increased yield, which was primarily attributed to an elevation in grain weight. Taken together, these results demonstrate that miR408 is a positive regulator of photosynthesis and that its genetic engineering is a promising route for enhancing photosynthetic performance and yield in diverse plants.

Perceptual Learning at a Conceptual Level.

Humans can learn to abstract and conceptualize the shared visual features defining an object category in object learning. Therefore, learning is generalizable to transformations of familiar objects and even to new objects that differ in other physical properties. In contrast, visual perceptual learning (VPL), improvement in discriminating fine differences of a basic visual feature through training, is commonly regarded as specific and low-level learning because the improvement often disappears when the trained stimulus is simply relocated or rotated in the visual field. Such location and orientation specificity is taken as evidence for neural plasticity in primary visual cortex (V1) or improved readout of V1 signals. However, new training methods have shown complete VPL transfer across stimulus locations and orientations, suggesting the involvement of high-level cognitive processes. Here we report that VPL bears similar properties of object learning. Specifically, we found that orientation discrimination learning is completely transferrable between luminance gratings initially encoded in V1 and bilaterally symmetric dot patterns encoded in higher visual cortex. Similarly, motion direction discrimination learning is transferable between first- and second-order motion signals. These results suggest that VPL can take place at a conceptual level and generalize to stimuli with different physical properties. Our findings thus reconcile perceptual and object learning into a unified framework. SIGNIFICANCE STATEMENT: Training in object recognition can produce a learning effect that is applicable to new viewing conditions or even to new objects with different physical properties. However, perceptual learning has long been regarded as a low-level form of learning because of its specificity to the trained stimulus conditions. Here we demonstrate with new training tactics that visual perceptual learning is completely transferrable between distinct physical stimuli. This finding indicates that perceptual learning also operates at a conceptual level in a stimulus-invariant manner.

Assessment of the Fluorescence Spectra Characteristics of Dissolved Organic Matter Derived from Organic Waste Composting Based on Projection Pursuit Classification (PPC).

The characteristics of fluorescence spectra of dissolved organic matter (DOM) derived from composting is one of the key ways to assess the compost maturity. However, the existing methods mainly focus on the qualitative description for the humification degree of compost. In this paper, projection pursuit classification (PPC) was conducted to quantitative assess the grades of compost maturity, based on the characteristics of fluorescence spectra of DOM. Eight organic wastes (chicken manure, swine manure, kitchen waste, lawn waste, fruits and vegetables waste, straw, green waste, and municipal solid waste) composting were conducted, the germination percentage (GI) and fluorescence spectra of DOM were measured during composting. Statistic analysis with all fluorescence parameters of DOM indicated that I436/I383 (a ratio between the fluorescence intensities at 436 and 383 nm in excitation spectra), FLR (an area ratio between fulvic-like region from 308 to 363 nm and total region in emission spectra), P(HA/Pro) (a regional integration ratio between humic acid-like region to protein-like region in excitation emission matrix (EEM) spectra), A4/A1 (an area ratio of the last quarter to the first quarter in emission spectra), r(A,C) (a ratio between the fluorescence intensities of peak A and peak C in EEM spectra) were correlated with each other (p < 0.01), suggesting that this fluorescence parameters could be considered as comprehensive evaluation index system of PPC. Subsequently, the four degrades of compost maturity included the best degree of maturity (I, GI > 80%), better degree of compost maturity (II, 60% < GI < 80%), maturity (III, 50% < GI < 60%), and immaturity (IV, GI < 50%) were divided according the GI value during composting. The corresponding fluorescence parameter values were calculated at each degrade of compost maturity. Then the projection values were calculated based on PPC considering the above fluorescence parameter values. The projection value was 2.01 - 2.22 for I grade, 1.21 - 2.0 for II grade, 0.57 - 1.2 for III grade, and 0.10 - 0.56 for IV grade. Model validation was then carried out with composts samples, the results indicated that the simulated values were agreed with the observed values, and the accuracy of PPC was 75% for four grades of maturity, and 100% for maturity and immaturity, suggesting that PPC could meet the need of the assessment of compost maturity.