Clustered regularly interspaced short palindromic repeats (CRISPR) activation (CRISPRa) has become an integral part of the molecular biology toolkit. CRISPRa genetic screens are an exciting high-throughput means of identifying genes the upregulation of which is sufficient to elicit a given phenotype. Activation machinery is continually under development to achieve greater, more robust, and more consistent activation. In this review, we offer a succinct technological overview of available CRISPRa architectures and a comprehensive summary of pooled CRISPRa screens. Furthermore, we discuss contemporary applications of CRISPRa across broad fields of research, with the aim of presenting a view of exciting emerging applications for CRISPRa screening.
BACKGROUND: Widescale evidence points to the involvement of glia and immune pathways in the progression of Alzheimer's disease (AD). AD-associated iPSC-derived glial cells show a diverse range of AD-related phenotypic states encompassing cytokine/chemokine release, phagocytosis and morphological profiles, but to date studies are limited to cells derived from PSEN1, APOE and APP mutations or sporadic patients. The aim of the current study was to successfully differentiate iPSC-derived microglia and astrocytes from patients harbouring an AD-causative PSEN2 (N141I) mutation and characterise the inflammatory and morphological profile of these cells. METHODS: iPSCs from three healthy control individuals and three familial AD patients harbouring a heterozygous PSEN2 (N141I) mutation were used to derive astrocytes and microglia-like cells and cell identity and morphology were characterised through immunofluorescent microscopy. Cellular characterisation involved the stimulation of these cells by LPS and Aß42 and analysis of cytokine/chemokine release was conducted through ELISAs and multi-cytokine arrays. The phagocytic capacity of these cells was then indexed by the uptake of fluorescently-labelled fibrillar Aß42. RESULTS: AD-derived astrocytes and microglia-like cells exhibited an atrophied and less complex morphological appearance than healthy controls. AD-derived astrocytes showed increased basal expression of GFAP, S100ß and increased secretion and phagocytosis of Aß42 while AD-derived microglia-like cells showed decreased IL-8 secretion compared to healthy controls. Upon immunological challenge AD-derived astrocytes and microglia-like cells showed exaggerated secretion of the pro-inflammatory IL-6, CXCL1, ICAM-1 and IL-8 from astrocytes and IL-18 and MIF from microglia. CONCLUSION: Our study showed, for the first time, the differentiation and characterisation of iPSC-derived astrocytes and microglia-like cells harbouring a PSEN2 (N141I) mutation. PSEN2 (N141I)-mutant astrocytes and microglia-like cells presented with a 'primed' phenotype characterised by reduced morphological complexity, exaggerated pro-inflammatory cytokine secretion and altered Aß42 production and phagocytosis.
Alzheimer Disease , Induced Pluripotent Stem Cells , Humans , Astrocytes/metabolism , Microglia/metabolism , Induced Pluripotent Stem Cells/metabolism , Interleukin-8/metabolism , Alzheimer Disease/genetics , Alzheimer Disease/metabolism , Cytokines/metabolism , Phenotype , Amyloid beta-Peptides/metabolism , Presenilin-2/genetics , Presenilin-2/metabolism
Despite the impressive advances in the synthesis of atomically precise graphene nanostructures witnessed during the last decade, advancing in compositional complexity faces major challenges. The concept of introducing the desired functional groups or dopants in the molecular precursor often fails due to their lack of stability during the reaction path. Here, a study on the stability of different pyridine and pyrimidine moieties during the on-surface synthesis of graphene nanoribbons on Au(111) is presented. Combining bond-resolved scanning tunneling microscopy with X-ray photoelectron spectroscopy, the thermal evolution of the nitrogen dopants throughout the whole reaction sequence is tracked. A comparative experimental and ab initio electronic characterization confirms the presence of dopants in the final structures, revealing also that the pyridinic nitrogen leads to a significant band downshift. The results demonstrate that, by using synthetic strategies to lower the reaction temperatures, one can preserve specific N-heterocycles throughout all the reaction steps of the synthesis of graphene nanoribbons and beyond the interibbon coupling reaction that leads to nanoporous graphene.
En el presente estudio se informa sobre los parásitos encontrados en un venado de cola blanca, Odocoileus virginianus peruvianus, capturado en el bosque seco del distrito de Paccha, provincia de Chota, departamento de Cajamarca. El Servicio Nacional Forestal y de Fauna Silvestre recuperó los parásitos de un espécimen macho adulto y las remitió al Centro de Investigación en Medicina Tropical de la Universidad Nacional de Cajamarca para la identificación taxonómica de helmintos y artrópodos, y análisis coproparasitológico. Se identificaron dos metacéstodos correspondientes a Cysticercus tenuicollis. En los análisis coproparasitológicos cualitativos se hallaron huevos de Nematodirus spp. en una carga de 10 por gramo de heces (h.p.g.) y 40 h.p.g. tipo Strongílidos que no pudieron diferenciarse por la baja carga en el coprocultivo. No se detectaron huevos de trematodos en la sedimentación. De ectoparásitos, se identificaron ocho garrapatas duras Rhipicephalus (Boophilus) microplus y cinco piojos chupadores Solenopotes binipilosus. Varios de los ejemplares fueron depositados en el Museo de Historia Natural de la Universidad Nacional Mayor de San Marcos, Lima. Los hallazgos representan el primer reporte formal de la garrapata común del ganado en esta subespecie de cérvido. Además, se registra por primera vez la presencia del piojo Solenopotes binipilosus en territorio peruano.
In the present study, findings regarding parasites discovered in a white-tailed deer, Odocoileus virginianus peruvianus, captured in the dry forest of the Paccha district, Chota province, Cajamarca department, are reported. The Servicio Nacional Forestal y de Fauna Silvestre recovered parasites from an adult male specimen and forwarded them to the Tropical Medicine Research Center at the Universidad Nacional de Cajamarca for taxonomic identification of helminths and arthropods, as well as coproparasitological analysis. Two metacestodes corresponding to Cysticercus tenuicollis were identified. Qualitative coproparasitological analyses revealed Nematodirus spp. eggs at a concentration of 10 eggs per gram of feces (EPG) and 40 EPG of Strongylid type that could not be differentiated due to low counts in the coproculture. No trematode eggs were detected in the sedimentation. Among ectoparasites, eight hard ticks Rhipicephalus (Boophilus) microplus and five sucking lice Solenopotes binipilosus were identified. Several specimens were deposited in the Museo de Historia Natural de la Universidad Nacional Mayor de San Marcos, Lima. These findings represent the first formal report of the common cattle tick in this subspecies of cervid. Additionally, the presence of the Solenopotes binipilosus louse in Peruvian territory is reported for the first time.
Resumen Se buscó identificar el perfil de motivación intrínseca (MI) y su relación con la perspectiva temporal en estudiantes universitarios del noroeste de México. En una muestra no probabilística por conveniencia de 553 estudiantes, se puso a prueba un modelo de motivación intrínseca, autoeficacia, orientación al logro, percepción escolar, morosidad y orientaciones temporales (pasado, presente y futuro). Se conformó un modelo estructural de MI que posee bondad de ajuste práctica adecuada. El modelo explica 48% de la variabilidad de la motivación intrínseca; destaca el efecto positivo de la orientación al logro (peso estructural=.65*) y el efecto negativo e indirecto (a través de la autoeficacia) de la morosidad (peso estructural=-.53*) sobre la MI. Y un efecto positivo de las orientaciones temporales (pasado negativo, presente hedonista y presente fatalista) sobre la morosidad (peso estructural=.54*). El estudio ofrece información sobre los aspectos que deben ser desarrollados en los estudiantes universitarios en relación con la motivación intrínseca.
Abstract The purpose of this study was to identify the intrinsic motivation (IM) profile and its relationship with time perspective in a non-probabilistic convenience sample of 553 students university students from a northwestern region in Mexico. Structural equation models were fitted for intrinsic motivation, with self-efficacy, achievement orientation, school perception, procrastination and temporal orientations (past, present and future) as direct and indirect predictors. A structural model of IM was formed that has adequate practical goodness-of-fit. The overall model explained 48% of the variance for intrinsic motivation. Achievement orientation was positively associated (structural weight =.65*) with intrinsic motivation while procrastination was negatively and indirectly (through self-efficacy) related (structural weight =.53*) to IM. Temporal orientations (negative past, hedonistic present and fatalistic present) were positively related to procrastination (structural weight =.54*). This study provides information regarding important predictors of intrinsic motivation that can be targeted among university students.
La biolixiviación, usando consorcios microbianos, es considera una alternativa ecoeficiente y de bajo costo para la recuperación de metales a partir de minerales de baja ley. En este estudio, se realizó la caracterización fisiológica y molecular de consorcios microbianos psicrotolerantes lixiviantes (CMPL), aislados de drenajes ácidos de minas de cuatro localidades mineras de las provincias de Pasco y Huarochirí, Perú, ubicados sobre los 4200 m de altitud. Se aislaron seis consorcios adaptados a medio 9K con ion ferroso y medio basal 9K con CuS al 0.5% p/v a 15 °C. Se evidenció la liberación de cobre en todos los consorcios. El CMPL con mejor crecimiento, presentó una recuperación de cobre de 12.47% en 30 días de evaluación. Los análisis de la secuenciación del gen ARNr 16S de la comunidad bacteriana, mostraron que los CMPL están dominados por el género Acidithiobacillus, seguido de Acidiphilium. En conclusión, se obtuvieron consorcios que pueden ser aplicados en biolixiviación de cobre en la minería altoandina.
Bioleaching, using microbial consortia, is regarded as an eco-efficient and cost-effective alternative for the recovery of metals from low-grade ores. In this study, we conducted physiological and molecular characterization of psychrotolerant leaching microbial consortia (PLMC) isolated from acid mine drainage in four mining sites within the Pasco and Huarochirí provinces of Peru, situated at altitudes above 4200 meters. Six consortia adapted to a medium containing ferrous ions (9K medium) and a basal medium with 0.5% w/v CuS at 15°C were isolated. All consortia exhibited copper release. The PLMC with the most robust growth achieved a copper recovery of 12.47% within 30 days of evaluation. 16S rRNA gene sequencing analysis of the bacterial community revealed that the PLMCs were predominantly dominated by the genus Acidithiobacillus, followed by Acidiphilium. In conclusion, consortia suitable for copper biolixiviation in high-altitude mining contexts were successfully obtained.
Patients with autoimmune conditions show a high expression of proinflammatory cytokines including interleukin (IL)-17. While IL-17 inhibitors have demonstrated efficacy in managing autoimmune disorders, rare instances of de novo or exacerbated inflammatory bowel disease (IBD) have been reported. The factors that affect the onset and severity remain unclear. Here, we present a case of a 38-year-old female who developed manifestations of Crohn's disease within 1 month of initiating secukinumab treatment for psoriatic arthritis, in addition to a review of the role of IL-17 in the pathophysiology of Crohn's disease.
Salmonella Gallinarum (SG) is a host-restricted enterobacteria and the causative agent of fowl typhoid in poultry. Here, we report the complete genomes of two strains belonging to this serotype. SA68 is a field strain isolated from the livers of dead hen carcasses of a commercial layer farm presenting high mortality located in São Paulo city, Brazil, in 1990. Strain 9R corresponds to a live attenuated SG commercial vaccine. DNA was extracted from pure cultures and subjected to whole genome sequencing (WGS) using the Ion Torrent PGM System. The assemblies reached lengths of 4,657,435 (SA68) and 4,657,471 (9R) base pairs. Complete genomes were deposited in GenBank under the accession numbers CP110192 (SA68) and CP110508 (9R). Both genomes were analyzed and compared in terms of molecular typing, antibiotic resistance genes, virulence genes, Salmonella pathogenic islands (SPIs), insertion sequences and prophages. The data obtained show many similarities in the genetic content, with the exception of the SPI-12 and CS54 pathogenic islands, which are exclusive to the field strain. The information generated will help to understand the virulence differences of field and vaccinal SG strains and can be used to perform evolutionary and epidemiologic studies.
Recent advances on surface-assisted synthesis have demonstrated that arrays of nanometer wide graphene nanoribbons can be laterally coupled with atomic precision to give rise to a highly anisotropic nanoporous graphene structure. Electronically, this graphene nanoarchitecture can be conceived as a set of weakly coupled semiconducting 1D nanochannels with electron propagation characterized by substantial interchannel quantum interferences. Here, we report the synthesis of a new nanoporous graphene structure where the interribbon electronic coupling can be controlled by the different degrees of freedom provided by phenylene bridges that couple the conducting channels. This versatility arises from the multiplicity of phenylene cross-coupling configurations, which provides a robust chemical knob, and from the interphenyl twist angle that acts as a fine-tunable knob. The twist angle is significantly altered by the interaction with the substrate, as confirmed by a combined bond-resolved scanning tunneling microscopy (STM) and ab initio analysis, and should accordingly be addressable by other external stimuli. Electron propagation simulations demonstrate the capability of either switching on/off or modulating the interribbon coupling by the corresponding use of the chemical or the conformational knob. Molecular bridges therefore emerge as efficient tools to engineer quantum transport and anisotropy in carbon-based 2D nanoarchitectures.
BACKGROUND: Urinary tract infections (UTI) are one of the most common pathologies in Mexico and the majority are caused by uropathogenic Escherichia coli (UPEC). UPEC possesses virulence and resistance determinants that promote UTI development and affect diagnosis and treatment. This study aims to systematically review published reports of virulence genes, antibiotic resistance, and phylogenetic groups prevalent in clinical isolates of UPEC in the Mexican population. METHODS: Systematic review with meta-analysis was performed following PRISMA guidelines. Articles in both English and Spanish were included. Total prevalence with a 95% confidence interval of each characteristic was calculated. Heterogeneity between studies and geographical areas was assessed by the Cochran Q test (Q), I-square (I2), and H-square (H2). Egger's test was used for risk of bias in publications and asymmetry evaluations. RESULTS: Forty-two articles were analyzed. The most prevalent virulence genes were ecp (97.25%; n = 364) and fimH (82.34%; n = 1,422), which are associated with lower UTI, followed by papGII (40.98%; n = 810), fliC (38.87%; n = 319), hlyA (23.55%; n = 1,521), responsible for with upper UTI. More than 78.13% (n = 1,893) of the isolates were classified as multidrug-resistant, with a higher prevalence of resistance to those antibiotics that are implemented in the basic regimen in Mexico. The most frequently reported Extended Spectrum ß-Lactamase (ESBL) was CTX-M-1 (55.61%; n = 392), and the predominant phylogroup was B2 (35.94%; n = 1,725). CONCLUSION: UPEC strains are responsible for a large portion of both lower and upper UTI in Mexico, and their multi-drug resistance drastically reduces the number of therapeutic options available.
Escherichia coli Infections , Urinary Tract Infections , Uropathogenic Escherichia coli , Humans , Virulence/genetics , Uropathogenic Escherichia coli/genetics , Escherichia coli Infections/drug therapy , Escherichia coli Infections/epidemiology , Virulence Factors/genetics , Virulence Factors/therapeutic use , Mexico/epidemiology , Phylogeny , Anti-Bacterial Agents/therapeutic use , Urinary Tract Infections/drug therapy , Urinary Tract Infections/epidemiology
Although ACE2 is the primary receptor for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, a systematic assessment of host factors that regulate binding to SARS-CoV-2 spike protein has not been described. Here, we use whole-genome CRISPR activation to identify host factors controlling cellular interactions with SARS-CoV-2. Our top hit was a TLR-related cell surface receptor called leucine-rich repeat-containing protein 15 (LRRC15). LRRC15 expression was sufficient to promote SARS-CoV-2 spike binding where they form a cell surface complex. LRRC15 mRNA is expressed in human collagen-producing lung myofibroblasts and LRRC15 protein is induced in severe Coronavirus Disease 2019 (COVID-19) infection where it can be found lining the airways. Mechanistically, LRRC15 does not itself support SARS-CoV-2 infection, but fibroblasts expressing LRRC15 can suppress both pseudotyped and authentic SARS-CoV-2 infection in trans. Moreover, LRRC15 expression in fibroblasts suppresses collagen production and promotes expression of IFIT, OAS, and MX-family antiviral factors. Overall, LRRC15 is a novel SARS-CoV-2 spike-binding receptor that can help control viral load and regulate antiviral and antifibrotic transcriptional programs in the context of COVID-19 infection.
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/metabolism , COVID-19/genetics , Antiviral Agents/pharmacology , Angiotensin-Converting Enzyme 2/metabolism , Fibroblasts/metabolism , Protein Binding , Membrane Proteins/genetics , Membrane Proteins/metabolism
Pathogenic strains of Escherichia coli threaten public health due to their virulence factors and antibiotic resistance. Additionally, the virulence of this bacterium varies by region depending on environmental conditions, agricultural practices, and the use of antibiotics and disinfectants. However, there is limited research on the prevalence of antibiotic-resistant E. coli in agriculture. Therefore, this research aimed to determine the antibiotic resistance of E. coli isolated from the Honeydew melon production system in Hermosillo, Sonora, Mexico. Thirty-two E. coli strains were isolated from 445 samples obtained from irrigation water, harvested melons, the hands of packaging workers, boxes, and discarded melons. The resistance profile of the E. coli strains was carried out to 12 antibiotics used in antimicrobial therapeutics against this bacterium; a high level of resistance to ertapenem (100%) was detected, followed by meropenem (97%), and ampicillin (94%); 47% of the strains were classified as multidrug-resistant. It was possible to identify the prevalence of the extended-spectrum ß-lactamase (ESBLs) gene blaTEM (15.6%), as well as the non-ESBL genes qepA (3.1%) and aac(6')lb-cr (3.1%). The E. coli strains isolated from irrigation water were significantly associated with resistance to aztreonam, cefuroxime, amikacin, and sulfamethoxazole/trimethoprim. Irrigation water, packing workers' hands, and discarded melons showed a higher prevalence of antibiotic-resistant, ESBL, and non-ESBL genes of E. coli strains in a farm and packing facility of Honeydew melon in Hermosillo, Sonora.
BACKGROUND: Multiplex polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (RFLP) for nuclear phosphoenolpyruvate carboxykinase (pepck) and polymerase delta (pold), respectively, have been used to differentiate Fasciola hepatica, F. gigantica, and hybrid Fasciola flukes. However, discrimination errors have been reported in both methods. This study aimed to develop a multiplex PCR based on a novel nuclear marker, the fatty acid binding protein type I (FABP) type I gene. METHODS: Nucleotide sequence variations of FABP type I were analyzed using DNA samples of F. hepatica, F. gigantica, and hybrid Fasciola flukes obtained from 11 countries in Europe, Latin America, Africa, and Asia. A common forward primer for F. hepatica and F. gigantica and two specific reverse primers for F. hepatica and F. gigantica were designed for multiplex PCR. RESULTS: Specific fragments of F. hepatica (290 bp) and F. gigantica (190 bp) were successfully amplified using multiplex PCR. However, the hybrid flukes contained fragments of both species. The multiplex PCR for FABP type I could precisely discriminate the 1312 Fasciola samples used in this study. Notably, no discrimination errors were observed with this novel method. CONCLUSIONS: Multiplex PCR for FABP type I can be used as a species discrimination marker in place of pepck and pold. The robustness of the species-specific primer should be continuously examined using a larger number of Fasciola flukes worldwide in the future since nucleotide substitutions in the primer regions may cause amplification errors.
Fasciola , Fascioliasis , Animals , Fasciola/genetics , Genetic Markers , Fatty Acid-Binding Proteins/genetics , Phosphoenolpyruvate , DNA, Helminth/genetics , Phosphoenolpyruvate Carboxykinase (ATP)/genetics , Nucleotides
COVID-19 patients display a wide range of disease severity, ranging from asymptomatic to critical symptoms with high mortality risk. Our ability to understand the interaction of SARS-CoV-2 infected cells within the lung, and of protective or dysfunctional immune responses to the virus, is critical to effectively treat these patients. Currently, our understanding of cell-cell interactions across different disease states, and how such interactions may drive pathogenic outcomes, is incomplete. Here, we developed a generalizable and scalable workflow for identifying cells that are differentially interacting across COVID-19 patients with distinct disease outcomes and use this to examine eight public single-cell RNA-seq datasets (six from peripheral blood mononuclear cells, one from bronchoalveolar lavage and one from nasopharyngeal), with a total of 211 individual samples. By characterizing the cell-cell interaction patterns across epithelial and immune cells in lung tissues for patients with varying disease severity, we illustrate diverse communication patterns across individuals, and discover heterogeneous communication patterns among moderate and severe patients. We further illustrate patterns derived from cell-cell interactions are potential signatures for discriminating between moderate and severe patients. Overall, this workflow can be generalized and scaled to combine multiple scRNA-seq datasets to uncover cell-cell interactions.
COVID-19 , Cell Communication , Humans , Leukocytes, Mononuclear , SARS-CoV-2 , Workflow
Cajamarca is an important Andean livestock production area located in northern Peru and at the same time endemic in a poorly studied disease known as paramphistomosis. The purpose of this research was to calculate the frequency of paramphistomids in sheep (Ovis aries) slaughtered in the Camal Municipal de Cajamarca, located in the city of Cajamarca. Between the months of February to September 2019, 386 samples of rumen-reticulum were collected that were later classified by age and origin of the animals. Transferred to the laboratory, the stomach contents were emptied; they were examined meticulously and exhaustively in order to find, collect and recognize the parasites adhering to the walls of the compartments. Nineteen samples were positive for Calicophoron microbothrioides in the rumen and none in the reticulum, thus obtaining a frequency of 4.92% in the presentation of paramphistomids in the sampled sheep. According to the origin, the town of Chanta presented a higher frequency with 9.09% and Bambamarca had the lowest frequency with 2.86%. In the age groups, sheep from 2 to 2.5 years old showed a 5.76% presence of paramphistomids and 3.33% of those 4 years old and older were positive. Pearson's correlation coefficient (r = -0.25473762) indicates that there is a low and inversely proportional negative relationship between age and frequency. Finally, with the Chi-square test, no significant difference was obtained between the place of origin and the number of positive cases.
Paramphistomatidae , Sheep Diseases , Trematoda , Trematode Infections , Animals , Peru/epidemiology , Sheep , Sheep Diseases/epidemiology , Sheep Diseases/parasitology , Trematode Infections/epidemiology , Trematode Infections/parasitology , Trematode Infections/veterinary
Triclabendazole (TCBZ) resistance is an emerging problem in fascioliasis that is not well understood. Studies including small numbers of parasites fail to capture the complexity of susceptibility variations between and within Fasciolahepatica populations. As the first step to studying the complex resistant phenotype−genotype associations, we characterized a large sample of adult F. hepatica with diverging TCBZ susceptibility. We collected parasites from naturally infected livestock slaughtered in the Cusco and Cajamarca regions of Peru. These parasites were exposed to TCBZ sulfoxide (TCBZ.SO) in vitro to determine their susceptibility. We used a motility score to determine the parasite's viability. We titrated drug concentrations and times to detect 20% non-viable (susceptible conditions) or 80% non-viable (resistant conditions) parasites. We exposed 3348 fully motile parasites to susceptible (n = 1565) or resistant (n = 1783) conditions. Three hundred and forty-one (21.8%) were classified as susceptible and 462 (25.9%) were classified as resistant. More resistant parasites were found in Cusco than in Cajamarca (p < 0.001). Resistant parasites varied by slaughterhouse (p < 0.001), month of the year (p = 0.008), fluke length (p = 0.016), and year of collection (p < 0.001). The in vitro susceptibility to TCBZ.SO in wildtype F. hepatica was associated with geography, season, and morphometry.
Acute kidney injury (AKI) can be a significant clue to solving a puzzling patient presentation. Postrenal AKI should be suspected if imaging shows any degree of hydronephrosis and can be caused by a variety of conditions. Diagnosis of urinary obstruction without significant dilatation of the pelvic-ureteral system requires a higher degree of suspicion, and hence, its identification can become late. In patients without prior cancer screening, the etiology of obstructive uropathy must be broadened to include primary or metastatic malignancy. Clinicians should look beyond the AKI to properly evaluate the etiology of the patient's presentation and symptoms. In this report, we present the case of a middle-aged female with no known past medical history who presented with AKI secondary to malignant retroperitoneal fibrosis as the first manifestation of metastatic breast cancer. Her AKI was associated with acute onset anuria and was found to have nondilated postrenal AKI with no significant abnormalities on renal imaging. Early onset anuria in the setting of AKI, which persists despite fluid resuscitation, can suggest complete urinary tract obstruction even with reassuring results of initial renal images, and in the patient with no history of cancer screening, malignancy should be suspected as a primary cause of obstructive uropathy.
Nanometer scale lateral heterostructures with atomically sharp band discontinuities can be conceived as the 2D analogues of vertical Van der Waals heterostructures, where pristine properties of each component coexist with interfacial phenomena that result in a variety of exotic quantum phenomena. However, despite considerable advances in the fabrication of lateral heterostructures, controlling their covalent interfaces and band discontinuities with atomic precision, scaling down components and producing periodic, lattice-coherent superlattices still represent major challenges. Here, a synthetic strategy to fabricate nanometer scale, coherent lateral superlattice heterojunctions with atomically sharp band discontinuity is reported. By merging interdigitated arrays of different types of graphene nanoribbons by means of a novel on-surface reaction, superlattices of 1D, and chemically heterogeneous nanoporous junctions are obtained. The latter host subnanometer quantum dipoles and tunneling in-gap states, altogether expected to promote interfacial phenomena such as interribbon excitons or selective photocatalysis.
