cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.34808/6mxs-an50
title: Carcinoma, undifferentiated, NOS - Female, 45 - Tissue image [3220630024695961]

description: This is the histopathological image of OVARY tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format. The detailed information about the patient, sample, and diagnosis are as follows: Patient:Age: 45Clinical description: Tumor of the right ovary.Gender: FemaleDiagnosis:Classification: ICD-O_3.2Classification code: EPITHELIAL NEOPLASMS, NOSDiagnosis: Carcinoma, undifferentiated, NOSResult of the histopathological examination: Undifferentiated carcinoma of the right ovary. IHC: vimentin (+), CK AE1/3 (+), Cam 5.2 (+), CK 7(+), CK 20 (-), EMA- focally +, PAX 8- focally (+), estrogen receptors (-), WT1 (-), p53-negative status, napsin A (-), HNF beta 1- focally (+), calretinin (-), podoplanin- focally (+), synaptophysin- focal weak reaction (+), chromogranin (-), inhibin (-), p16- negative status, TTF 1 (-), CEA (-), HMB 45 (-), Melan A (-), mammoglobin (-), GCDFP15 (-), CDX 2 (-), Ki 67 80%, mucikarmin- focally weak (+).Sample:Material: FFPECollecting method: Surgical specimenTopography: FEMALE GENITAL ORGANSOrgan: OVARYTissue: OvaryType of staining: positive/IHCStaining: Not applicableAntibody: CDX-2Technology:Equipment: Pannoramic 250 3DHistechLens: 20xOrganization:Source: Medical University Gdańsk
DOI: 10.48370/ofd/acti2n
title: Myodes glareolus - 13178, Zoological collection of the Mammal Research Institute, PAS

description: Myodes glareolus (Bank vole) from Zoological collection of the Mammal Research Institute, PAS. Collected 1955-08-30, in: Białowieża National Park, Poland. Material type:
DOI: 10.34808/9b5x-yh64
title: Abdominal pregnancy - Female, 37 - Tissue image [903073001350701]

description: This is the histopathological image of PLACENTA tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format. The detailed information about the patient, sample, and diagnosis are as follows: Patient:Age: 37Clinical description: 3rd pregnancy Hbd 40Gender: FemaleDiagnosis:Classification: ICD-10_10-20Classification code: Chapter XV - Pregnancy, childbirth and the puerperiumDiagnosis: Abdominal pregnancyResult of the histopathological examination: Three-vessel umbilical cord with the usual histological structure.Sample:Material: FFPECollecting method: Surgical specimenTopography: FEMALE GENITAL ORGANSOrgan: PLACENTATissue: PlacentaType of staining: positive/HEStaining: Not applicableAntibody: Not applicableTechnology:Equipment: Pannoramic 250 3DHistechLens: 20xOrganization:Source: Medical University Gdańsk
DOI: 10.48370/ofd/scou2m
title: Myodes glareolus - 9586, Zoological collection of the Mammal Research Institute, PAS

description: Myodes glareolus (Bank vole) from Zoological collection of the Mammal Research Institute, PAS. Collected 1955-06-30, in: Białowieża National Park, Poland. Material type:
DOI: 10.34808/zf0k-0m77
title: Edwards' syndrome, unspecified - Male, 1 - Tissue image [307063001018431]

description: This is the histopathological image of BRAIN tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format. The detailed information about the patient, sample, and diagnosis are as follows: Patient:Age: 1Clinical description: Prematurity. Asphyxia. Suspicion of Edwards syndrome (trisomy 18). Lived 6 days.Gender: MaleDiagnosis:Classification: ICD-10_10-20Classification code: Chapter XVII - Congenital malformations, deformations and chromosomal abnormalitiesDiagnosis: Edwards' syndrome, unspecifiedResult of the histopathological examination: In the pons segments visible signs of edema, hyperemia and minor haemorrhages.Sample:Material: FFPECollecting method: Autopsy specimenTopography: EYE, BRAIN AND OTHER PARTS OF CENTRAL NERVOUS SYSTEMOrgan: BRAINTissue: Brain stemType of staining: positive/HEStaining: Not applicableAntibody: Not applicableTechnology:Equipment: Pannoramic 250 3DHistechLens: 20xOrganization:Source: Medical University Gdańsk
DOI: 10.34808/3yg6-hh16
title: Pneumonia, unspecified - Male, 49 - Tissue image [9010729561463821]

description: This is the histopathological image of BRONCHUS AND LUNG tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format. The detailed information about the patient, sample, and diagnosis are as follows: Patient:Age: 49Clinical description: A patient with a usual interstitial pneumonia diagnosed on HRCT 3 years earlier. A lung has been sent for histopathological assessment following right lung transplantation.Gender: MaleDiagnosis:Classification: ICD-10_10-20Classification code: Chapter X - Diseases of the respiratory systemDiagnosis: Pneumonia, unspecifiedResult of the histopathological examination: Usual interstitial pneumonia. Areas of fibrosis at the periphery of the lung with associated chronic interstitial inflammation. In addition, there are cystic spaces lined by bronchiolar epithelium as well as fibroblast foci and fibrosis (honeycomb pattern).Sample:Material: FFPECollecting method: Surgical specimenTopography: RESPIRATORY SYSTEM AND INTRATORACIC ORGANSOrgan: BRONCHUS AND LUNGTissue: Lung, NOSType of staining: positive/HEStaining: Not applicableAntibody: Not applicableTechnology:Equipment: Pannoramic 250 3DHistechLens: 20xOrganization:Source: Medical University Gdańsk
DOI: 10.34808/cp67-ys83
title: Spitz nevus, NOS - Female, 31 - Tissue image [7110729594545221]

description: This is the histopathological image of SKIN tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format. The detailed information about the patient, sample, and diagnosis are as follows: Patient:Age: 31Clinical description: 0,7 cm dome-shaped light-brown lesion of skin of arm.Gender: FemaleDiagnosis:Classification: ICD-O_3.2Classification code: NEVI AND MELANOMASDiagnosis: Spitz nevus, NOSResult of the histopathological examination: Spitz neavus. Complete excision. HMB-45+, Melan-A+.Sample:Material: FFPECollecting method: Excision of lesionsTopography: SKINOrgan: SKINTissue: Skin of armType of staining: positive/IHCStaining: Not applicableAntibody: Melan ATechnology:Equipment: Pannoramic 250 3DHistechLens: 20xOrganization:Source: Medical University Gdańsk
DOI: 10.34808/20ye-h449
title: Classical Hodgkin lymphoma, nodular sclerosis, NOS - Male, 57 - Tissue image [5020730020692711]

description: This is the histopathological image of LYMPH NODES tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format. The detailed information about the patient, sample, and diagnosis are as follows: Patient:Age: 57Clinical description: Enlarged cervical lymph nodes.Gender: MaleDiagnosis:Classification: ICD-O_3.2Classification code: CHOROBA HODGKINADiagnosis: Classical Hodgkin lymphoma, nodular sclerosis, NOSResult of the histopathological examination: Classical Hodgkin Lymphoma- nodular sclerosis. RS cells: CD30+ (membranous reaction), CD15+, Ki-67+, MUM1+, Pax5 weak+, CD3-, CD20-, EBV-.Sample:Material: FFPECollecting method: Surgical specimenTopography: LYMPH NODESOrgan: LYMPH NODESTissue: Cervical lymph nodeType of staining: positive/IHCStaining: Not applicableAntibody: CD 30Technology:Equipment: Pannoramic 250 3DHistechLens: 20xOrganization:Source: Medical University Gdańsk
DOI: 10.48370/ofd/7rysg4
title: Myodes glareolus - 8329, Zoological collection of the Mammal Research Institute, PAS

description: Myodes glareolus (Bank vole) from Zoological collection of the Mammal Research Institute, PAS. Collected 1955-05-29, in: Białowieża National Park, Poland. Material type:
DOI: 10.34808/vst9-b931
title: Invasive breast carcinoma of no special type - Female, 52 - Tissue image [10100730045409771]

description: This is the histopathological image of BREAST tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format. The detailed information about the patient, sample, and diagnosis are as follows: Patient:Age: 52Clinical description: 2 cm palpable tumor of right breast.Gender: FemaleDiagnosis:Classification: ICD-O_3.2Classification code: DUCTAL AND LOBULAR NEOPLASMSDiagnosis: Invasive breast carcinoma of no special typeResult of the histopathological examination: Invasive breast carcinoma NOS: NHG 2 (3+3+1: 5 mitoses/10 HPF). Ductal carcinoma in situ (DCIS) NG2 (solid variant). ER+, PR+, HER2-. Ki-67 10%.Sample:Material: FFPECollecting method: Surgical specimenTopography: BREASTOrgan: BREASTTissue: Upper-outer quadrant of breastType of staining: positive/IHCStaining: Not applicableAntibody: ERTechnology:Equipment: Pannoramic 250 3DHistechLens: 20xOrganization:Source: Medical University Gdańsk
DOI: 10.34808/0s0d-t187
title: Endometrial stromal sarcoma, low grade - Female, 42 - Tissue image [1270630012699731]

description: This is the histopathological image of CORPUS UTERI tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format. The detailed information about the patient, sample, and diagnosis are as follows: Patient:Age: 42Clinical description: 6,4 x 5 x 4 cm tumor of uterus.Gender: FemaleDiagnosis:Classification: ICD-O_3.2Classification code: COMPLEX MIXED AND STROMAL NEOPLASMSDiagnosis: Endometrial stromal sarcoma, low gradeResult of the histopathological examination: Endometrial stromal sarcoma, low grade: CD10+, PR+, SMA+, h-caldesmone-, CD31-, Cyclin D1 + in 30% cells, Ki-67 10%.Sample:Material: FFPECollecting method: Surgical specimenTopography: FEMALE GENITAL ORGANSOrgan: CORPUS UTERITissue: Corpus uteriType of staining: positive/HCStaining: Gomori Silver Impregnation (Reticulum)Antibody: Not applicableTechnology:Equipment: Pannoramic 250 3DHistechLens: 20xOrganization:Source: Medical University Gdańsk
DOI: 10.34808/dwv1-gr39
title: Secondary malignant neoplasm of retroperitoneum and peritoneum - Male, 48 - Tissue image [7210730002091901]

description: This is the histopathological image of RETROPERITONEUM AND PERITONEUM tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format. The detailed information about the patient, sample, and diagnosis are as follows: Patient:Age: 48Clinical description: Tumour of the peritoneum.Gender: MaleDiagnosis:Classification: ICD-10_10-20Classification code: Chapter II - NeoplasmsDiagnosis: Secondary malignant neoplasm of retroperitoneum and peritoneumResult of the histopathological examination: Low-differentiated carcinoma, partially signet ring cell carcinoma, infiltrating the peritoneum.
CDX-2 (+)Sample:Material: FFPECollecting method: Surgical specimenTopography: RETROPERITONEUM AND PERITONEUMOrgan: RETROPERITONEUM AND PERITONEUMTissue: Specified parts of peritoneumType of staining: positive/IHCStaining: Not applicableAntibody: CDX-2Technology:Equipment: Pannoramic 250 3DHistechLens: 20xOrganization:Source: Medical University Gdańsk
DOI: 10.48370/ofd/bnkkjh
title: Myodes glareolus - 74262, Zoological collection of the Mammal Research Institute, PAS

description: Myodes glareolus (Bank vole) from Zoological collection of the Mammal Research Institute, PAS. Collected 1968-05-17, in: Białowieża National Park, Poland. Material type:
DOI: 10.34808/79sp-vt41
title: Neuroblastoma, NOS - Female, 2 - Tissue image [5240730032352071]

description: This is the histopathological image of ADRENAL GLAND tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format. The detailed information about the patient, sample, and diagnosis are as follows: Patient:Age: 2Clinical description: Tumor of the adrenal gland.Gender: FemaleDiagnosis:Classification: ICD-O_3.2Classification code: NEUROEPITHELIOMATOUS NEOPLASMSDiagnosis: Neuroblastoma, NOSResult of the histopathological examination: Neuroblastoma, schwannian stroma poor, differentiating subtypeSample:Material: FFPECollecting method: Surgical specimenTopography: THYROID AND OTHER ENDOCRINE GLANDSOrgan: ADRENAL GLANDTissue: Medulla of adrenal glandType of staining: positive/HEStaining: Not applicableAntibody: Not applicableTechnology:Equipment: Pannoramic 250 3DHistechLens: 20xOrganization:Source: Medical University Gdańsk
DOI: 10.34808/h4vg-b751
title: Plexiform neurofibroma - Male, 60 - Tissue image [9020730024816481]

description: This is the histopathological image of BRAIN tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format. The detailed information about the patient, sample, and diagnosis are as follows: Patient:Age: 60Clinical description: Suspicion of neurofibroma of the brain.Gender: MaleDiagnosis:Classification: ICD-O_3.2Classification code: NERVE SHEATH TUMORSDiagnosis: Plexiform neurofibromaResult of the histopathological examination: Plexiform neurofibroma.
(IHC: S100 +, CD34 +, NFP (-), EMA (-), indeks Ki67 ok. 1%).Sample:Material: FFPECollecting method: Surgical specimenTopography: EYE, BRAIN AND OTHER PARTS OF CENTRAL NERVOUS SYSTEMOrgan: BRAINTissue: Posterior cranial fossaType of staining: positive/HEStaining: Not applicableAntibody: Not applicableTechnology:Equipment: Pannoramic 250 3DHistechLens: 20xOrganization:Source: Medical University Gdańsk
DOI: 10.48370/ofd/iskkza
title: Myodes glareolus - 117666, Zoological collection of the Mammal Research Institute, PAS

description: Myodes glareolus (Bank vole) from Zoological collection of the Mammal Research Institute, PAS. Collected 1975-10-18, in: Białowieża National Park, Poland. Material type:
DOI: 10.34808/4xgm-vv80
title: Pleural plaque without asbestos - Female, 70 - Tissue image [3280730025603061]

description: This is the histopathological image of HEART, MEDIASTINUM, AND PLEURA tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format. The detailed information about the patient, sample, and diagnosis are as follows: Patient:Age: 70Clinical description: Leasion of the pleura.Gender: FemaleDiagnosis:Classification: ICD-10_10-20Classification code: Chapter X - Diseases of the respiratory systemDiagnosis: Pleural plaque without asbestosResult of the histopathological examination: Pleural plaque.Sample:Material: FFPECollecting method: Surgical biopsyTopography: RESPIRATORY SYSTEM AND INTRATORACIC ORGANSOrgan: HEART, MEDIASTINUM, AND PLEURATissue: Pleura, NOSType of staining: positive/HEStaining: Not applicableAntibody: Not applicableTechnology:Equipment: Pannoramic 250 3DHistechLens: 20xOrganization:Source: Medical University Gdańsk
DOI: 10.34808/shn0-x717
title: Mumps - Male, 4 - Tissue image [5170730021232231]

description: This is the histopathological image of LYMPH NODES tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format. The detailed information about the patient, sample, and diagnosis are as follows: Patient:Age: 4Clinical description: Gender: MaleDiagnosis:Classification: ICD-10_10-20Classification code: Chapter I - Certain infectious and parasitic diseasesDiagnosis: MumpsResult of the histopathological examination: Sample:Material: FFPECollecting method: Surgical specimenTopography: LYMPH NODESOrgan: LYMPH NODESTissue: Submandibular lymph nodeType of staining: positive/IHCStaining: Not applicableAntibody: KappaTechnology:Equipment: Pannoramic 250 3DHistechLens: 20xOrganization:Source: Medical University Gdańsk
DOI: 10.34808/80dx-9e94
title: Hurthle cell carcinoma - Not available, 65 - Tissue image [3300730069472631]

description: This is the histopathological image of THYROID GLAND tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format. The detailed information about the patient, sample, and diagnosis are as follows: Patient:Age: 65Clinical description: A thyroid lobe measuring 5.5x4x4 cm. An ill-defined, beige tumor measuring approximately 4.4x2.8x2 cm was present on sectioning.Gender: Not availableDiagnosis:Classification: ICD-O_3.2Classification code: ADENOMAS AND ADENOCARCINOMASDiagnosis: Hurthle cell carcinomaResult of the histopathological examination: Hurtle cell carcinoma, widely invasive. Tumor confined to the thyroid gland removed completely. Features of angioinvasion in single blood vessels at the periphery of the tumor are present. IHC: calcitonin(-), synaptophysin (-/+), chromogranin A(-), TTF1(+), Ki67 10%. Mitotic figures: 1/10 HPF.Sample:Material: FFPECollecting method: Surgical specimenTopography: THYROID AND OTHER ENDOCRINE GLANDSOrgan: THYROID GLANDTissue: Thyroid, NOSType of staining: positive/HEStaining: Not applicableAntibody: Not applicableTechnology:Equipment: Pannoramic 250 3DHistechLens: 20xOrganization:Source: Medical University Gdańsk
DOI: 10.48370/ofd/pb7gje
title: Myodes glareolus - 10430, Zoological collection of the Mammal Research Institute, PAS

description: Myodes glareolus (Bank vole) from Zoological collection of the Mammal Research Institute, PAS. Collected 1955-07-11, in: Białowieża National Park, Poland. Material type:
DOI: 10.34808/q5cc-c123
title: Melanoma, metastatic - Male, 65 - Tissue image [9140730014156011]

description: This is the histopathological image of LYMPH NODES tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format. The detailed information about the patient, sample, and diagnosis are as follows: Patient:Age: 65Clinical description: 5 cm firm tumor in right groin. CT: numerous enlarged lymph nodes in abdominal cavity.Gender: MaleDiagnosis:Classification: ICD-O_3.2Classification code: NEVI AND MELANOMASDiagnosis: Melanoma, metastaticResult of the histopathological examination: Metastasis of melanoma: S100+, SOX10+, Melan A+, HMB45+, CKAE1/AE3-, LCA-.Sample:Material: FFPECollecting method: Core-needle biopsyTopography: LYMPH NODESOrgan: LYMPH NODESTissue: Inguinal lymph nodeType of staining: positive/IHCStaining: Not applicableAntibody: s100Technology:Equipment: Pannoramic 250 3DHistechLens: 20xOrganization:Source: Medical University Gdańsk
DOI: 10.34808/gahp-rr36
title: Paget disease, extramammary - Male, 64 - Tissue image [2270630026327731]

description: This is the histopathological image of SKIN tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format. The detailed information about the patient, sample, and diagnosis are as follows: Patient:Age: 64Clinical description: Redness of skin of right groin (3,5 cm diameter). History of extramammary Paget disease of left groin.Gender: MaleDiagnosis:Classification: ICD-O_3.2Classification code: DUCTAL AND LOBULAR NEOPLASMSDiagnosis: Paget disease, extramammaryResult of the histopathological examination: Extramammary Paget disease of skin: CKAE1/AE3+, CK7+, HER2+, CK19+, CAM5.2+, CK20-, CDX2-, TTF1-, Napsin-, HMB45-.Sample:Material: FFPECollecting method: Excision of lesionsTopography: SKINOrgan: SKINTissue: Skin of groinType of staining: positive/HEStaining: Not applicableAntibody: Not applicableTechnology:Equipment: Pannoramic 250 3DHistechLens: 20xOrganization:Source: Medical University Gdańsk
DOI: 10.34808/ned2-9x78
title: Moderate cervical dysplasia - Female, 50 - Tissue image [5130730017408051]

description: This is the histopathological image of CERVIX UTERI tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format. The detailed information about the patient, sample, and diagnosis are as follows: Patient:Age: 50Clinical description: Cervical erosion. CIN2 confirmed  in biopsyGender: FemaleDiagnosis:Classification: ICD-10_10-20Classification code: Chapter XIV - Diseases of the genitourinary systemDiagnosis: Moderate cervical dysplasiaResult of the histopathological examination: The mucosa of the endocervix locally polypoid, with squamous metaplasia and small-glandular hyperplasia, with chronic active inflammation and the presence of diffuse foci of external endometriosis in the stroma, with   "tunnel clusters" gland growth and the formation of numerous retention mucous cysts.Sample:Material: FFPECollecting method: Surgical specimenTopography: FEMALE GENITAL ORGANSOrgan: CERVIX UTERITissue: Cervical canalType of staining: positive/HEStaining: Not applicableAntibody: Not applicableTechnology:Equipment: Pannoramic 250 3DHistechLens: 20xOrganization:Source: Medical University Gdańsk
DOI: 10.48370/ofd/6flbdw
title: Myodes glareolus - 148820, Zoological collection of the Mammal Research Institute, PAS

description: Myodes glareolus (Bank vole) from Zoological collection of the Mammal Research Institute, PAS. Collected 1983-09-27, in: Białowieża National Park, Poland. Material type:
DOI: 10.34808/h1f1-qq08
title: Inflammatory disease of cervix uteri - Female, 46 - Tissue image [3130630016424891]

description: This is the histopathological image of CERVIX UTERI tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: VS200 Olympus slide scanner (20x magnification) and saved to DICOM format. The detailed information about the patient, sample, and diagnosis are as follows: Patient:Age: 46Clinical description: Leyomyomas of the uterus.Gender: FemaleDiagnosis:Classification: ICD-10_10-20Classification code: Chapter XIV - Diseases of the genitourinary systemDiagnosis: Inflammatory disease of cervix uteriResult of the histopathological examination: Endocervix with features of diffuse laminar endocervical hyperplasia.Sample:Material: FFPECollecting method: Autopsy specimenTopography: FEMALE GENITAL ORGANSOrgan: CERVIX UTERITissue: External osType of staining: positive/HEStaining: Not applicableAntibody: Not applicableTechnology:Equipment: VS200 OlympusLens: 20xOrganization:Source: Medical University Gdańsk