Pillar[5]arene-Based 3D Hybrid Supramolecular Polymer for Green Catalysis in Water

Pillar[n]arene-based supramolecular polymers have attracted great interest because of their tunable morphologies and external stimuli responsiveness. However, most of the investigations of supramolecular polymers previously reported were focused on their formation and transformation, and investigations on their applications are rare. Herein, we designed and prepared hybrid polymeric materials by incorporating Pd nanoparticles into a supramolecular polymer, constructed from a pillar[5]arene dimer and a three-arm guest. The obtained hybrid polymer was fully characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, scanning electron microscopy-energy-dispersive X-ray mapping, and X-ray diffraction technologies. Importantly, the hybrid supramolecular polymeric materials exhibited desirable catalytic activity for reductions of toxic nitroaromatics and C-C bond-forming Suzuki-Miyaura reaction in aqueous solution.

Accelerated anaerobic biodecolorization of sulfonated azo dyes by magnetite nanoparticles as potential electron transfer mediators

Anaerobic decolorization of azo dyes has been evidenced to be an economical and effective pretreatment method, but its generally limited by the low decolorization efficiency, especially for biodecolorization sulfonated azo dyes. In this study, magnetite nanoparticles (MNPs) as a conductive material, was coupled into anaerobic system for enhancing decolorization of sulfonated azo dyes, i.e., methyl orange (MO), with technology feasibility and system stability emphasized. The results showed that the anaerobic decolorization capacity was significantly enhanced with addition of MNPs (at dose of 1 g/L), where the efficiencies of MO decolorization and aromatic amines formation were as high as 97.28 ± 0.78 % and 99.44 ± 0.25%, respectively. In addition, both electron transport system activity and sludge conductivity were also significantly improved, suggesting that a direct extracellular electron transfer had been successfully established via MNPs as RMs. Under continuous-flow experiments, addition of MNPs not only improved anaerobic system resistance environmental stress (e.g., high MO concentration, low hydraulic retention time and low co-substance concentration) but also accelerated sludge granulation. The relative abundance of functional species related to dissimilatory iron reduction and MO biodegradation were also enriched under MNPs stimulation. The observed long-term stable performance suggests the full-scale application potential of this coupled system for treatment of wastewater containing sulfonated azo dyes.

Pillar[5]arene-Based [2]Rotaxane: Synthesis, Characterization, and Application in a Coupling Reaction

Mechanically interlocked molecules are a class of smart supramolecular species because of their interesting topological structure and application in various areas, such as biology and nanoscience. In this work, we used "multicomponent reaction" to fabricate a new [2]rotaxane based on pillar[5]arene from different small-sized molecules. The molecular structure of the obtained [2]rotaxane R was confirmed by ¹H and ¹³C NMR, high-resolution electrospray ionization mass spectrometry, two-dimensional nuclear Overhauser effect spectroscopy, and density functional theory studies. Interestingly, the [2]rotaxane-based organometallic cross-linked catalyst (Pd@R) was easily constructed via the coordination between triazole groups and Pd(NO₃)₂. Pd@R proved to be a good catalyst for the Suzuki-Miyaura coupling reaction with excellent stability and repeatability.

Anti-LDLR modified TPZ@Ce6-PEG complexes for tumor hypoxia-targeting chemo-/radio-/photodynamic/photothermal therapy

Hypoxia, a state of low oxygen tension in solid tumors, is not only closely correlated with resistance to both radiotherapy and chemotherapy, but also associated with poor prognosis of tumors and regional lymph node status. Herein, based on the analysis of cell samples from tumor patients, low-density lipoprotein receptor (LDLR) was found to be overexpressed on the surface of hypoxic tumor cell membranes, and confirmed to be an effective hypoxia marker through specific binding with anti-LDLR antibody in solid tumors. In addition, using the special therapeutic microenvironment of hypoxia, tirapazamine (TPZ, which can be used as both a hypoxia-activated chemotherapy prodrug and radiotherapy sensitizer) was integrated with PEGylated photosensitizer chlorin e6 (Ce6-PEG) by self-assembly, and anti-LDLR was then modified on the surface to form tumor hypoxia-targeting multifunctional nanoparticles (CPTA). CPTA possesses a multimodal antitumor effect via a simultaneous photothermal therapy (PTT)/photodynamic therapy (PDT) effect generated by Ce6, and chemotherapy/radiotherapy actions sensitized by TPZ. It is noteworthy that tumor oxygen was consumed in the process of PDT and the hypoxia was subsequently exacerbated, which can greatly increase the TPZ-sensitized chemotherapy and lead to a synergistic antitumor effect. Both in vitro and in vivo experiments demonstrated that CPTA possesses an excellent therapeutic effect through PTT, PDT, and TPZ sensitized radiotherapy and chemotherapy. This hypoxic tumor targeting synergetic therapeutic strategy has great potential for future clinical transformation.

Synthesis and optoelectronic properties of spirofluorenexanthene-based carbazole host materials

The structure–property relationship of carbazole substituted SFX derivatives at different positions for RGB PhOLEDs.

pH/glutathione-responsive release of SO2 induced superoxide radical accumulation for gas therapy of cancer

A pH/glutathione (GSH)-responsive SO₂ generation nanoplatform (BODS NPs) is established to achieve lysosomal escape and GSH depletion in tumors to sensitize the SO₂-mediated oxidative stress.

A three-dimensional BODIPY–iron(iii) compound with improved H2O2-response for NIR-II photoacoustic imaging guided chemodynamic/photothermal therapy

3D boron dipyrromethene (BODIPY)–Fe(iii) coordination polymer nanoparticles with NIR-II absorption were developed as photothermal and chemodynamic agent to effectively kill cancer cells.

[Comparison of modeling effects of two different 7, 12-dimethylbenz[a] anthracene induced breast cancer models in tree shrew]

Objective: To explore the feasibility of 7, 12-dimethylbenz[a] anthracene (DMBA) induced tree shrew breast cancer model, and compare the effects of two administration modes by gavage and mammary gland injection. Methods: A total of 40 tree shrews were randomly divided into two groups (20 animals per group): DMBA gavage group and mammary gland injection group. DMBA was dissolved in edible vegetable oil. For gavage group, tree shrews were administered with DMBA solutions (15 mg/kg) by gavage once a day. For mammary gland injection group, DMBA solution (10 mg/kg) was injected into the mammary fat pad of tree shrews, and the injection was performed for a total of 3 times. From the first administration of DMBA, medroxyprogesterone acetate (MPA, 100 mg/kg) was intramuscularly injected into the muscles of the lateral thighs of tree shrews at the same time, for a total of 5 times. The tumorigenesis and survival of tree shrews were monitored. The tumor histological morphology was observed by HE staining. The expression of estrogen receptor (ER), progesterone receptor (PR), cytokeratin5/6 (CK5/6) and human epidermal factor receptor-2 (HER-2) was detected by immunohistochemical staining. Results: In the gavage group, there were 10 deaths, and 4 tree shrews developed mammary tumors with 20.0% (4/20) tumor formation rate. The success rate of mammary cancer modeling was 10.0% (2/20), and the tumor formation time was 197.3±15.1 days. In the mammary gland injection group, there were 8 tree shrews died, and 9 tree shrews formed tumors with 45.0% (9/20) tumor formation rate. The success rate of mammary cancer modeling was 40.0% (8/20), and the tumor formation time was 71.8±19.0 days. There was no significant difference in mortality and tumor formation rate (P>0.05) between the two groups (all P>0.05). However, in the mammary gland injection group, the success rate of mammary cancer modeling was significantly higher than that in the gavage group (P<0.05), whereas the tumor formation time was markedly shorter than that in the gavage group (P<0.01). The pathological types in the gavage group included ductal hyperplasia, intraductal papilloma and ductal carcinoma in situ, while those in the breast injection group included intraductal papilloma and ductal carcinoma in situ. In both groups, immunohistochemical staining showed the negative expression of HER-2 but positive expression of ER, PR and CK5/6 with varying degrees. Conclusion: Both the DMBA gavage and mammary gland injection can successfully establish the tree shrew breast cancer model, and the modeling effect of mammary gland injection is better than gavage.

Hierarchical Uniform Supramolecular Conjugated Spherulites with Suppression of Defect Emission

Easily processed, well-defined, and hierarchical uniform artificial architectures with intrinsic strong crystalline emission properties are necessary for a range of light-emitting optoelectronic devices. Herein, we designed and prepared ordered supramolecular spherulites, comprising planar conformational molecules as primary structures and multiple hydrogen bonds as physical cross-links. Compared with serious aggregation-induced fluorescence quenching (up to 70%), these highly ordered architectures exhibited unique and robust crystalline emission with a high PLQY of 55%, which was much higher than those of other terfluorenes. The primary reasons for the high PLQY are the uniform exciton energetic landscape created in the planar conformation and the highly ordered molecular packing in spherulite. Meanwhile, minimal residual defect (green-band) emissions are effectively suppressed in our oriented crystalline framework, whereas the strong and stable blue light radiations are promoted. These findings may confirm that supramolecular ordered artificial architectures may offer higher control and tunability for optoelectronic applications.

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Coplanar molecular conformation is stabilized in supramolecular crystalline frameworks

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Spiro-terfluorene can self-assemble into hierarchical well-defined spherulites

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Ordered and uniform condensed structures suppress defect emission

Functional black phosphorus nanosheets for mitochondria-targeting photothermal/photodynamic synergistic cancer therapy

A mitochondria-targeting nanosystem, BP@PDA–Ce6&TPP NSs, has been constructed, and exhibit excellent performance in imaging-guided synergistic photothermal and photodynamic cancer therapy.

Organelle-targeting nanosystems are envisioned as promising tools for phototherapy, which can generate heat or reactive oxygen species (ROS) induced cytotoxicity in the targeted location but leave the surrounding biological tissues undamaged. In this work, an imaging-guided mitochondria-targeting photothermal/photodynamic nanosystem has been developed on the basis of functionalized black phosphorus (BP) nanosheets (NSs). In the nanosystem, BP NSs are coated with polydopamine (PDA) and then covalently linked with both chlorin e6 (Ce6) and triphenyl phosphonium (TPP) through carbodiimide reaction between the amino group and the carboxyl group, forming BP@PDA–Ce6&TPP NSs. Due to the strong absorbance of BP@PDA in the near-infrared region and the highly efficient ROS generation of Ce6, the as-prepared nanosystem with mitochondria-targeting capacity (TPP moiety) shows remarkably enhanced efficiency in cancer cell killing. Combined photothermal and photodynamic therapy is implemented and monitored by in vivo fluorescence imaging, achieving excellent performance in inhibiting tumor growth. This study presents a novel nanotheranostic agent for mitochondria-targeting phototherapy, which may open new horizons for biomedicine.

Supramolecular Design of Donor-Acceptor Complexes via Heteroatom Replacement toward Structure and Electrical Transporting Property Tailoring

A feasible strategy relies on using heteroatom replacement, namely, chemical modification of an organic compound. Here we present this design concept for donor-acceptor complexes, which involves introducing nitrogen atoms to the middle ring of donor molecules to promote short contacts and reduce steric effect of the mixed framework. These nitrogen-modified complexes can possess a shorter molecular distance besides the mixed-stacking pathway, enlarged π-π interactions, or even a scarce 1:2.5 molar ratio through extra acceptor insertion. As a result, the unique 1:2 complex with nitrogen atoms on the different sides demonstrated stable electron field-effect mobility performance, whereas the binary system with no nitrogen replacement or N atoms on the identical sides displayed poor ambipolar properties. These results confirmed that heteroatom replacement was a powerful molecular design tool to fine-tune the molecular packing of organic donor-acceptor complexes and their corresponding electronic properties.

Ultrastable Supramolecular Self-Encapsulated Wide-Bandgap Conjugated Polymers for Large-Area and Flexible Electroluminescent Devices

Controlling chain behavior through smart molecular design provides the potential to develop ultrastable and efficient deep-blue light-emitting conjugated polymers (LCPs). Herein, a novel supramolecular self-encapsulation strategy is proposed to construct a robust ultrastable conjugated polydiarylfluorene (PHDPF-Cz) via precisely preventing excitons from interchain cross-transfer/coupling and contamination from external trace H₂ O/O₂ . PHDPF-Cz consists of a mainchain backbone where the diphenyl groups localize at the 9-position as steric bulk moieties, and carbazole (Cz) units localize at the 4-position as supramolecular π-stacked synthon with the dual functionalities of self-assembly capability and hole-transport facility. The synergistic effect of the steric bulk groups and π-stacked carbazoles affords PHDPF-Cz as an ultrastable property, including spectral, morphological stability, and storage stability. In addition, PHDPF-Cz spin-coated gelation films also show thickness-insensitive deep-blue emission with respect to the reference polymers, which are suitable to construct solution-processed large-scale optoelectronic devices with higher reproducibility. High-quality and uniform deep-blue emission is observed in large-area solution-processed films. The electroluminescence shows high-quality deep-blue intrachain emission with a CIE (0.16, 0.12) and a very narrow full width at half-maximum of 32 nm. Finally, large-area and flexible polymer light-emitting devices with a single-molecular excitonic behavior are also fabricated. The supramolecular self-encapsulation design provides an effective strategy to construct ultrastable LCPs for optoelectronic applications.

Tumor-Microenvironment-Responsive Nanoconjugate for Synergistic Antivascular Activity and Phototherapy

Insufficient oxygen supply (hypoxia), short half-life (<40 ns) of singlet oxygen, and up-regulation of the heat shock protein expression in solid tumors impede the photodynamic and photothermal therapeutic efficacy. Herein, a near-infrared carrier-free nanoconjugate direct-acting antiviral (DAA) with synergistic antivascular activity and pH-responsive photodynamic/photothermal behavior was designed and synthesized to improve cancer treatment efficacy. Obtained by the self-assembly approach, the biocompatible DAA nanoparticles (NPs) displayed amplifying pH-responsive photodynamic/photothermal performance in an acidic tumor microenvironment due to the protonation of diethylaminophenyl units. Most important, the antivascular agent 5,6-dimethylxanthenone-4-acetic acid, targeting the vascular endothelial growth factor, can be smartly released from the pro-drug DAA via ester bond hydrolysis at the subacid endocytosis organelles in the endothelial cells, which can effectively destroy the vascular region to prevent tumor proliferation and metastasis. Hence, DAA NPs can specifically target vascular endothelial cells and tumorous lysosomes with desired cellular damage properties in vitro. Therefore, the tumors can be ablated completely with no recurrence and side effects in vivo, which implies that DAA NPs provide a promising approach for cancer treatment via synergistic antivascular activity and photodynamic/photothermal therapy.

Promotion of Para-Chlorophenol Reduction and Extracellular Electron Transfer in an Anaerobic System at the Presence of Iron-Oxides

Anaerobic dechlorination of chlorophenols often subjects to their toxicity and recalcitrance, presenting low loading rate and poor degradation efficiency. In this study, in order to accelerate p-chlorophenol (p-CP) reduction and extracellular electron transfer in an anaerobic system, three iron-oxide nanoparticles, namely hematite, magnetite and ferrihydrite, were coupled into an anaerobic system, with the performance and underlying role of iron-oxide nanoparticles elucidated. The reductive dechlorination of p-CP was notably improved in the anaerobic systems coupled by hematite and magnetite, although ferrihydrite did not plays a positive role. Enhanced dechlorination of p-CP in hematite or magnetite coupled anaerobic system was linked to the obvious accumulation of acetate, lower oxidation-reduction potential and pH, which were beneficial for reductive dechlorination. Electron transfer could be enhanced by Fe2+/Fe3+ redox couple on the iron oxides surface formed through dissimilatory iron-reduction. This study demonstrated that the coupling of iron-oxide nanoparticles such as hematite and magnetite could be a promising alternative to the conventional anaerobic reduction process for the removal of CPs from wastewater.

Steric-Hindrance-Functionalized Polydiarylfluorenes: Conformational Behavior, Stabilized Blue Electroluminescence, and Efficient Amplified Spontaneous Emission

Control of the hierarchical molecular organization of polydiarylfluorenes by synthetic strategies is significant for optimizing photophysical properties as well as the performance of light-emitting devices. Herein, for the suppression of molecular aggregation and enhancement of luminescence efficiency, a series of steric units were introduced into polydiarylfluorenes by copolymerization, with the aim of integrating the advantages of the steric-hindrance effect and of the β-phase. Optical and Raman spectroscopies revealed a β-phase conformation for a polymer copolymerized with spiro[fluorene-9,9'-xanthene] (SFX), with photoluminescence (PL) peaks at 454, 482, and 517 nm. Moreover, the morphological stability and electroluminescence (EL) stability were also improved without compromising the performance of the polymer light-emitting diodes (PLEDs). Furthermore, three steric-hindrance-functionalized copolymers showed significantly decreased thresholds for amplified spontaneous emission (E_th^ASE) and enhanced stability following thermal annealing treatment. These results indicate that steric-hindrance functionalization is a superior approach to improve the overall stability and optoelectronic properties for blue-light-emitting π-conjugated polymers.

Structure-Property Study on Two New D-A Type Materials Comprising Pyridazine Moiety and the OLED Application as Host

In this paper, two new pyridazine based donor-acceptor type materials, i.e., 3CzPyaPy: 9,9'-(3-(6-(9H-carbazol-9-yl)pyridazin-3-yl)pyridine-2,6-diyl)bis(9H-carbazole) and 4CzPyPyaPy: 3,6-bis(2,6-di(9H-carbazol-9-yl)pyridin-3-yl)pyridazine, were synthesized with high yields. These two materials exhibited strong absorption/emission with high molar extinction coefficients and moderate photoluminescence quantum yield. The glass transition temperature of 3CzPyaPy was detected to be as high as 131 °C, showing its high thermal stability. Although the absorption energies and oxidation/reduction behaviors of the two materials were similar, the emission from 4CzPyPyaPy with longer effective-conjugation length presented hypsochromic shift both in films and in dilute solutions, contradicting to the common sense. The single crystal structure study disclosed their different space stretching and packing: 3CzPyaPy was twisted in larger angles and adopted dimerlike packing, while 4CzPyPyaPy showed smaller torsion angles and exhibited slipped herringbone packing. The dimerlike packing in 3CzPyaPy is responsible for its bathochromic shift of emission in solid state, while its unsymmetrical molecular structure accounts for that in solution. We believe that the unsymmetrical molecular structure of 3CzPyaPy is partially responsible for its high thermal-stability and also responsible for its HOMO dispersion which renders it slightly more difficult to oxidize. 3CzPyaPy was proved to be a bipolar-transport material and when served as a phosphor host, a green phosphorescent device achieved maximum efficiencies of 54.0 cd A^-1, 42.4 lm W^-1, and 17.7%, which are among the best with nonoptimized device structure, demonstrating its great potential for optoelectronic application. Furthermore, the new synthesized pyridazine derivatives and the corresponding structural and molecular-packing influences on material properties give a new insight into molecule tailoring.

Reuse of Fenton sludge as an iron source for NiFe2O4 synthesis and its application in the Fenton-based process

The potentially hazardous iron-containing sludge from the Fenton process requires proper treatment and disposal, which often results in high treatment cost. In this study, a novel method for the reuse of Fenton sludge as an iron source for the synthesis of nickel ferrite particles (NiFe₂O₄) is proposed. Through a co-precipitation method followed by sintering at 800°C, magnetic NiFe₂O₄ particles were successfully synthesized, which was confirmed by powder X-ray diffraction (XRD), scanning electronic microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy. The synthesized NiFe₂O₄ could be used as an efficient catalyst in the heterogeneous Fenton process. In phenol degradation with H₂O₂ or NiFe₂O₄ alone, the phenol removal efficiencies within the reaction time of 330min were as low as 5.9%±0.1% and 13.5%±0.4%, respectively. However, in the presence of both NiFe₂O₄ and H₂O₂, phenol removal efficiency as high as 95%±3.4% could be achieved, indicating the excellent catalytic performance of NiFe₂O₄ in the heterogeneous Fenton process. Notably, a rapid electron exchange between Ni^II and Fe^III ions in the NiFe₂O₄ structure could be beneficial for the Fenton reaction. In addition, the magnetic catalyst was relatively stable, highly active and recoverable, and has potential applications in the Fenton process for organic pollutant removal.

Inhibition of the integrin/FAK signaling axis and c-Myc synergistically disrupts ovarian cancer malignancy

Integrins, a family of heterodimeric receptors for extracellular matrix, are promising therapeutic targets for ovarian cancer, particularly high-grade serous-type (HGSOC), as they drive tumor cell attachment, migration, proliferation and survival by activating focal adhesion kinase (FAK)-dependent signaling. Owing to the potential off-target effects of FAK inhibitors, disruption of the integrin signaling axis remains to be a challenge. Here, we tackled this barrier by screening for inhibitors being functionally cooperative with small-molecule VS-6063, a phase II FAK inhibitor. From this screening, JQ1, a potent inhibitor of Myc oncogenic network, emerged as the most robust collaborator. Treatment with a combination of VS-6063 and JQ1 synergistically caused an arrest of tumor cells at the G2/M phase and a decrease in the XIAP-linked cell survival. Our subsequent mechanistic analyses indicate that this functional cooperation was strongly associated with the concomitant disruption of activation or expression of FAK and c-Myc as well as their downstream signaling through the PI3K/Akt pathway. In line with these observations, we detected a strong co-amplification or upregulation at genomic or protein level for FAK and c-Myc in a large portion of primary tumors in the TCGA or a local HGSOC patient cohort. Taken together, our results suggest that the integrin–FAK signaling axis and c-Myc synergistically drive cell proliferation, survival and oncogenic potential in HGSOC. As such, our study provides key genetic, functional and signaling bases for the small-molecule-based co-targeting of these two distinct oncogenic drivers as a new line of targeted therapy against human ovarian cancer.

Carbon Cationic Relay via Superelectrophiles: Synthesis of Spiro-diazafluorenes

Superelectrophilic-initiated carbon cationic relay reactions of diazafluorenones with phenols were developed to provide strategically novel and atom-economic access to spirodiazafluorenes via tandem Friedel-Crafts reaction, nucleophilic addition, and intramolecular cyclization sequences. A range of spirodiazafluorenes that are difficult to synthesize with traditional protocols has been constructed successfully in middle to high yields using this method.

Long-Term Homeostatic Properties Complementary to Hebbian Rules in CuPc-Based Multifunctional Memristor

Most simulations of neuroplasticity in memristors, which are potentially used to develop artificial synapses, are confined to the basic biological Hebbian rules. However, the simplex rules potentially can induce excessive excitation/inhibition, even collapse of neural activities, because they neglect the properties of long-term homeostasis involved in the frameworks of realistic neural networks. Here, we develop organic CuPc-based memristors of which excitatory and inhibitory conductivities can implement both Hebbian rules and homeostatic plasticity, complementary to Hebbian patterns and conductive to the long-term homeostasis. In another adaptive situation for homeostasis, in thicker samples, the overall excitement under periodic moderate stimuli tends to decrease and be recovered under intense inputs. Interestingly, the prototypes can be equipped with bio-inspired habituation and sensitization functions outperforming the conventional simplified algorithms. They mutually regulate each other to obtain the homeostasis. Therefore, we develop a novel versatile memristor with advanced synaptic homeostasis for comprehensive neural functions.

Coupling of iron shavings into the anaerobic system for enhanced 2,4-dinitroanisole reduction in wastewater

Packing of iron powder into anaerobic system is attractive for enhancing removal of recalcitrant pollutants from wastewater, but is limited by various inherent drawbacks of iron powder, such as easy precipitation and poor mass transfer. To address the above issues, iron shavings were packed into an upflow anaerobic sludge blanket (UASB) for enhancing 2,4-dinitroanisole (DNAN) reduction in this study, with system stability and microbial biodiversity emphasized. The results showed that both DNAN reduction and 2,4-diaminoanisole (DAAN) formation could be notably improved in the iron shavings coupled UASB system. Moreover, the ability to resist environmental stress was also strengthened through the addition of iron shavings in the UASB reactor. Compared with a loose and rough surface of the sludge in the control UASB reactor, the sludge in the coupled system presented a compact, rigid and granular appearance under iron shavings simulation. Furthermore, high throughput sequencing analysis indicated that the diversity of microbial community in the iron shavings coupled UASB system was significantly higher than that of the control UASB reactor. Additionally, species related to DNAN reduction and methane production were enriched in the coupled system. The observed long-term stable performance highlights the full-scale application potential of iron shavings coupled anaerobic sludge process for the treatment of nitroaromatic compounds containing wastewater.